Terminal apparatus, base station apparatus, and communication method

ABSTRACT

A method by a user equipment (UE) is described. The method includes receiving, from a base station, a first radio resource control (RRC) parameter, monitoring a physical downlink control channel (PDCCH) with a first DCI format, receiving a transport block (TB) in a physical downlink shared channel (PDSCH) scheduled by the PDCCH with the first DCI format, wherein the first RRC parameter contains one or more MCS entries, each entry provides a modulation order and a target code rate, determining a modulation order and a target code rate used for the TB in the PDSCH at least based on a modulation code scheme (MCS) field and one, a part, or all of a plurality of specified DCI fields other than the MCS field.

TECHNICAL FIELD

The present disclosure relates to a terminal apparatus, a base stationapparatus, a communication method, and an integrated circuit.

BACKGROUND

At present, as a radio access system and a radio network technologyaimed for the fifth generation cellular system, technical investigationand standard development are being conducted, as extended standards ofLong Term Evolution (LTE), on LTE-Advanced Pro (LTE-A Pro) and New Radiotechnology (NR) in The Third Generation Partnership Project (3GPP).

In the fifth generation cellular system, three services of enhancedMobile BroadBand (eMBB) to achieve high-speed and large-volumetransmission, Ultra-Reliable and Low Latency Communication (URLLC) toachieve low-latency and high-reliability communication, and massiveMachine Type Communication (mMTC) to allow connection of a large numberof machine type devices such as Internet of Things (IoT) have beendemanded as assumed scenarios.

For example, wireless communication devices may communicate with one ormore devices for multiple service types. However, current existingsystems and methods may only offer limited flexibility and efficiencyfor multiple service communication. As illustrated by this discussion,systems and methods according to the prevent invention, supporting anMCS field with variable bits, may improve communication reliability andefficiency and may be beneficial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating one configuration of one or morebase stations and one or more user equipments (UEs) in which systems andmethods for search space configuration and/or DCI alignment may beimplemented;

FIG. 2 is a diagram illustrating a RRC parameter SearchSpace with aninformation element structure A 200;

FIG. 3 is a diagram illustrating a RRC parameter SearchSpace-v16 with aninformation element structure B 300;

FIG. 4 is a diagram illustrating a RRC parameter SearchSpace-v16 with aninformation element structure C 400;

FIG. 5 is a diagram illustrating one example of MCS index table 500.

FIG. 6 is a flow diagram illustrating one implementation of a method 600for determining Q_(m), R, and TBS by a UE 102.

FIG. 7 is a diagram illustrating one example of configured MCS indextable by RRC parameter 700.

FIG. 8 is a flow diagram illustrating one implementation of a method 800for determining Q_(m), R, and TBS by a base station 160.

FIG. 9 illustrates various components that may be utilized in a UE;

FIG. 10 illustrates various components that may be utilized in a basestation;

DESCRIPTION OF EMBODIMENTS

A method by a user equipment (UE) is described. The method includesreceiving, from a base station, a first radio resource control (RRC)parameter, monitoring a physical downlink control channel (PDCCH) with afirst DCI format, receiving a transport block (TB) in a physicaldownlink shared channel (PDSCH) scheduled by the PDCCH with the firstDCI format, wherein the first RRC parameter contains one or more MCSentries, each entry provides a modulation order and a target code rate,determining a modulation order and a target code rate used for the TB inthe PDSCH at least based on a modulation and coding scheme (MCS) fieldand one, a part, or all of a plurality of specified DCI fields otherthan the MCS field. The specified DCI fields include one, a part, or allof a HARQ process number field, a New data indicator (NDI) field, a timedomain resource assignment field, and a frequency domain resourceassignment field. In a first case that the PDSCH is determined as aninitial transmission of the TB based on the NDI field of the first DCIformat, the modulation order and the target code rate are determined asX-th MCS entry in the first RRC parameter, the determined code rate isat least used to determine the transport block size for the TB. In asecond case that the PDSCH is determined as a retransmission of the TBbased on the NDI field of the first DCI format, the modulation order isdetermined as X-th MCS entry in the first RRC parameter, the target coderate provided in the X-th MCS entry is not used for the TB in the PDSCH.The value of X is indicated by the MCS field.

A method by a base station is described. The method includestransmitting, to a user equipment (UE), a first radio resource control(RRC) parameter, wherein the first RRC parameter contains one or moreMCS entries, each entry provides a modulation order and a target coderate, determining a modulation order and a target code rate used for atransport block (TB) at least based on the first RRC parameter and one,a part, or all of a plurality of specified DCI fields other than amodulation and coding scheme (MCS) field, generate the MCS field with anMCS index indicating the determined modulation order and the target coderate, further transmitting a physical downlink control channel (PDCCH)with a first DCI format including the generated MCS field, to transmitthe TB in a physical downlink shared channel (PDSCH) scheduled by thePDCCH with the first DCI format. The specified DCI fields include one, apart, or all of a HARQ process number field, a New data indicator (NDI)field, a time domain resource assignment field, and a frequency domainresource assignment field. In a first case that the PDSCH is determinedas an initial transmission of the TB based on the NDI field of the firstDCI format, the modulation order and the target code rate are determinedas X-th MCS entry in the first RRC parameter, the determined code rateis at least used to determine the transport block size for the TB. In asecond case that the PDSCH is determined as a retransmission of the TBbased on the NDI field of the first DCI format, the modulation order isdetermined as X-th MCS entry in the first RRC parameter, the target coderate provided in the X-th MCS entry is not used for the TB in the PDSCH.The value of X is indicated by the MCS field.

A user equipment (UE) is described. The UE includes reception circuitryconfigured to receive, from a base station, a first radio resourcecontrol (RRC) parameter, to monitor a physical downlink control channel(PDCCH) with a first DCI format, to receive a transport block (TB) in aphysical downlink shared channel (PDSCH) scheduled by the PDCCH with thefirst DCI format, wherein the first RRC parameter contains one or moreMCS entries, each entry provides a modulation order and a target coderate, control circuitry configured to determine a modulation order and atarget code rate used for the TB in the PDSCH at least based on amodulation and coding scheme (MCS) field and one, a part, or all of aplurality of specified DCI fields other than the MCS field. Thespecified DCI fields include one, a part, or all of a HARQ processnumber field, a New data indicator (NDI) field, a time domain resourceassignment field, and a frequency domain resource assignment field. In afirst case that the PDSCH is determined as an initial transmission ofthe TB based on the NDI field of the first DCI format, the modulationorder and the target code rate are determined as X-th MCS entry in thefirst RRC parameter, the determined code rate is at least used todetermine the transport block size for the TB. In a second case that thePDSCH is determined as a retransmission of the TB based on the NDI fieldof the first DCI format, the modulation order is determined as X-th MCSentry in the first RRC parameter, the target code rate provided in theX-th MCS entry is not used for the TB in the PDSCH. The value of X isindicated by the MCS field.

A base station is described. The base station includes transmissioncircuitry configured to transmit, to a user equipment (UE), a firstradio resource control (RRC) parameter, wherein the first RRC parametercontains one or more MCS entries, each entry provides a modulation orderand a target code rate, control circuitry configured to determine amodulation order and a target code rate used for a transport block (TB)at least based on the first RRC parameter and one, a part, or all of aplurality of specified DCI fields other than a modulation and codingscheme (MCS) field, generate the MCS field with an MCS index indicatingthe determined modulation order and the target code rate, transmissioncircuitry configured to further transmit a physical downlink controlchannel (PDCCH) with a first DCI format including the generated MCSfield, to transmit the TB in a physical downlink shared channel (PDSCH)scheduled by the PDCCH with the first DCI format. The specified DCIfields include one, a part, or all of a HARQ process number field, a Newdata indicator (NDI) field, a time domain resource assignment field, anda frequency domain resource assignment field. In a first case that thePDSCH is determined as an initial transmission of the TB based on theNDI field of the first DCI format, the modulation order and the targetcode rate are determined as X-th MCS entry in the first RRC parameter,the determined code rate is at least used to determine the transportblock size for the TB. In a second case that the PDSCH is determined asa retransmission of the TB based on the NDI field of the first DCIformat, the modulation order is determined as X-th MCS entry in thefirst RRC parameter, the target code rate provided in the X-th MCS entryis not used for the TB in the PDSCH. The value of X is indicated by theMCS field.

3GPP Long Term Evolution (LTE) is the name given to a project to improvethe Universal Mobile Telecommunications System (UMTS) mobile phone ordevice standard to cope with future requirements. In one aspect, UMTShas been modified to provide support and specification for the EvolvedUniversal Terrestrial Radio Access (E-UTRA) and Evolved UniversalTerrestrial Radio Access Network (E-UTRAN). 3GPP NR (New Radio) is thename given to a project to improve the LTE mobile phone or devicestandard to cope with future requirements. In one aspect, LTE has beenmodified to provide support and specification (TS 38.331, 38.321,38.300, 37.300, 38.211, 38.212, 38.213, 38.214, etc) for the New RadioAccess (NR) and Next generation-Radio Access Network (NG-RAN).

At least some aspects of the systems and methods disclosed herein may bedescribed in relation to the 3GPP LTE, LTE-Advanced (LTE-A),LTE-Advanced Pro, New Radio Access (NR), and other 3G/4G/5G standards(e.g., 3GPP Releases 8, 9, 10, 11, 12, 13, 14, and/or 15, and/or NarrowBand-Internet of Things (NB-IoT)). However, the scope of the presentdisclosure should not be limited in this regard. At least some aspectsof the systems and methods disclosed herein may be utilized in othertypes of wireless communication systems.

A wireless communication device may be an electronic device used tocommunicate voice and/or data to a base station, which in turn maycommunicate with a network of devices (e.g., public switched telephonenetwork (PSTN), the Internet, etc.). In describing systems and methodsherein, a wireless communication device may alternatively be referred toas a mobile station, a UE (User Equipment), an access terminal, asubscriber station, a mobile terminal, a remote station, a userterminal, a terminal, a subscriber unit, a mobile device, a relay node,etc. Examples of wireless communication devices include cellular phones,smart phones, personal digital assistants (PDAs), laptop computers,netbooks, e-readers, wireless modems, etc. In 3GPP specifications, awireless communication device is typically referred to as a UE. However,as the scope of the present disclosure should not be limited to the 3GPPstandards, the terms “UE” and “wireless communication device” may beused interchangeably herein to mean the more general term “wirelesscommunication device.”

In 3GPP specifications, a base station is typically referred to as agNB, a Node B, an eNB, a home enhanced or evolved Node B (HeNB) or someother similar terminology. As the scope of the disclosure should not belimited to 3GPP standards, the terms “base station,”, “gNB”, “Node B,”“eNB,” and “HeNB” may be used interchangeably herein to mean the moregeneral term “base station.” Furthermore, one example of a “basestation” is an access point. An access point may be an electronic devicethat provides access to a network (e.g., Local Area Network (LAN), theInternet, etc.) for wireless communication devices. The term“communication device” may be used to denote both a wirelesscommunication device and/or a base station.

It should be noted that as used herein, a “cell” may be anycommunication channel that is specified by standardization or regulatorybodies to be used for International Mobile Telecommunications-Advanced(IMT-Advanced), IMT-2020 (5G) and all of it or a subset of it may beadopted by 3GPP as licensed bands (e.g., frequency bands) to be used forcommunication between a base station and a UE. It should also be notedthat in NR, NG-RAN, E-UTRA and E-UTRAN overall description, as usedherein, a “cell” may be defined as “combination of downlink andoptionally uplink resources.” The linking between the carrier frequencyof the downlink resources and the carrier frequency of the uplinkresources may be indicated in the system information transmitted on thedownlink resources.

“Configured cells” are those cells of which the UE is aware and isallowed by a base station to transmit or receive information.“Configured cell(s)” may be serving cell(s). The UE may receive systeminformation and perform the required measurements on configured cells.“Configured cell(s)” for a radio connection may consist of a primarycell and/or no, one, or more secondary cell(s). “Activated cells” arethose configured cells on which the UE is transmitting and receiving.That is, activated cells are those cells for which the UE monitors thephysical downlink control channel (PDCCH) and in the case of a downlinktransmission, those cells for which the UE decodes a physical downlinkshared channel (PDSCH). “Deactivated cells” are those configured cellsthat the UE is not monitoring the transmission PDCCH. It should be notedthat a “cell” may be described in terms of differing dimensions. Forexample, a “cell” may have temporal, spatial (e.g., geographical) andfrequency characteristics.

The base stations may be connected by the NG interface to the 5G-corenetwork (5G-CN). 5G-CN may be called as to NextGen core (NGC), or 5Gcore (5GC). The base stations may also be connected by the S1 interfaceto the evolved packet core (EPC). For instance, the base stations may beconnected to a NextGen (NG) mobility management function by the NG-2interface and to the NG core User Plane (UP) functions by the NG-3interface. The NG interface supports a many-to-many relation between NGmobility management functions, NG core UP functions and the basestations. The NG-2 interface is the NG interface for the control planeand the NG-3 interface is the NG interface for the user plane. Forinstance, for EPC connection, the base stations may be connected to amobility management entity (MME) by the S1-MME interface and to theserving gateway (S-GW) by the S1-U interface. The S1 interface supportsa many-to-many relation between MMEs, serving gateways and the basestations. The S1-MME interface is the S1 interface for the control planeand the S1-U interface is the S1 interface for the user plane. The Uuinterface is a radio interface between the UE and the base station forthe radio protocol.

The radio protocol architecture may include the user plane and thecontrol plane. The user plane protocol stack may include packet dataconvergence protocol (PDCP), radio link control (RLC), medium accesscontrol (MAC) and physical (PHY) layers. A DRB (Data Radio Bearer) is aradio bearer that carries user data (as opposed to control planesignaling). For example, a DRB may be mapped to the user plane protocolstack. The PDCP, RLC, MAC and PHY sublayers (terminated at the basestation 460 a on the network) may perform functions (e.g., headercompression, ciphering, scheduling, ARQ and HARQ) for the user plane.PDCP entities are located in the PDCP sublayer. RLC entities may belocated in the RLC sublayer. MAC entities may be located in the MACsublayer. The PHY entities may be located in the PHY sublayer.

The control plane may include a control plane protocol stack. The PDCPsublayer (terminated in base station on the network side) may performfunctions (e.g., ciphering and integrity protection) for the controlplane. The RLC and MAC sublayers (terminated in base station on thenetwork side) may perform the same functions as for the user plane. TheRadio Resource Control (RRC) (terminated in base station on the networkside) may perform the following functions. The RRC may perform broadcastfunctions, paging, RRC connection management, radio bearer (RB) control,mobility functions, UE measurement reporting and control. The Non-AccessStratum (NAS) control protocol (terminated in MME on the network side)may perform, among other things, evolved packet system (EPS) bearermanagement, authentication, evolved packet system connection management(ECM)-IDLE mobility handling, paging origination in ECM-IDLE andsecurity control.

Signaling Radio Bearers (SRBs) are Radio Bearers (RB) that may be usedonly for the transmission of RRC and NAS messages. Three SRBs may bedefined. SRB0 may be used for RRC messages using the common controlchannel (CCCH) logical channel. SRB1 may be used for RRC messages (whichmay include a piggybacked NAS message) as well as for NAS messages priorto the establishment of SRB2, all using the dedicated control channel(DCCH) logical channel. SRB2 may be used for RRC messages which includelogged measurement information as well as for NAS messages, all usingthe DCCH logical channel. SRB2 has a lower-priority than SRB1 and may beconfigured by a network (e.g., base station) after security activation.A broadcast control channel (BCCH) logical channel may be used forbroadcasting system information. Some of BCCH logical channel may conveysystem information which may be sent from the network to the UE via BCH(Broadcast Channel) transport channel. BCH may be sent on a physicalbroadcast channel (PBCH). Some of BCCH logical channel may convey systeminformation which may be sent from the network to the UE via DL-SCH(Downlink Shared Channel) transport channel. Paging may be provided byusing paging control channel (PCCH) logical channel.

For example, the DL-DCCH logical channel may be used (but not limitedto) for a RRC reconfiguration message, a RRC reestablishment message, aRRC release, a UE Capability Enquiry message, a DL Information Transfermessage or a Security Mode Command message. UL-DCCH logical channel maybe used (but not limited to) for a measurement report message, a RRCReconfiguration Complete message, a RRC Reestablishment Completemessage, a RRC Setup Complete message, a Security Mode Complete message,a Security Mode Failure message, a UE Capability Information, message, aUL Handover Preparation Transfer message, a UL Information Transfermessage, a Counter Check Response message, a UE Information Responsemessage, a Proximity Indication message, a RN (Relay Node)Reconfiguration Complete message, an MBMS Counting Response message, aninter Frequency RSTD Measurement Indication message, a UE AssistanceInformation message, an In-device Coexistence Indication message, anMBMS Interest Indication message, an SCG Failure Information message.DL-CCCH logical channel may be used (but not limited to) for a RRCConnection Reestablishment message, a RRC Reestablishment Rejectmessage, a RRC Reject message, or a RRC Setup message. UL-CCCH logicalchannel may be used (but not limited to) for a RRC ReestablishmentRequest message, or a RRC Setup Request message.

System information may be divided into the MasterInformationBlock (MIB)and a number of SystemInformationBlocks (SIBs).

The UE may receive one or more RRC messages from the base station toobtain RRC configurations or parameters. The RRC layer of the UE mayconfigure RRC layer and/or lower layers (e.g., PHY layer, MAC layer, RLClayer, PDCP layer) of the UE according to the RRC configurations orparameters which may be configured by the RRC messages, broadcastedsystem information, and so on. The base station may transmit one or moreRRC messages to the UE to cause the UE to configure RRC layer and/orlower layers of the UE according to the RRC configurations or parameterswhich may be configured by the RRC messages, broadcasted systeminformation, and so on.

When carrier aggregation is configured, the UE may have one RRCconnection with the network. One radio interface may provide carrieraggregation. During RRC establishment, re-establishment and handover,one serving cell may provide Non-Access Stratum (NAS) mobilityinformation (e.g., a tracking area identity (TAI)). During RRCre-establishment and handover, one serving cell may provide a securityinput. This cell may be referred to as the primary cell (PCell). In thedownlink, the component carrier corresponding to the PCell may be thedownlink primary component carrier (DL PCC), while in the uplink it maybe the uplink primary component carrier (UL PCC).

Depending on UE capabilities, one or more SCells may be configured toform together with the PCell a set of serving cells. In the downlink,the component carrier corresponding to an SCell may be a downlinksecondary component carrier (DL SCC), while in the uplink it may be anuplink secondary component carrier (UL SCC).

The configured set of serving cells for the UE, therefore, may consistof one PCell and one or more SCells. For each SCell, the usage of uplinkresources by the UE (in addition to the downlink resources) may beconfigurable. The number of DL SCCs configured may be larger than orequal to the number of UL SCCs and no SCell may be configured for usageof uplink resources only.

From a UE viewpoint, each uplink resource may belong to one servingcell. The number of serving cells that may be configured depends on theaggregation capability of the UE. The PCell may only be changed using ahandover procedure (e.g., with a security key change and a random accessprocedure). A PCell may be used for transmission of the PUCCH. A primarysecondary cell (PSCell) may also be used for transmission of the PUCCH.The PSCell may be referred to as a primary SCG cell or SpCell of asecondary cell group. The PCell or PSCell may not be de-activated.Re-establishment may be triggered when the PCell experiences radio linkfailure (RLF), not when the SCells experience RLF. Furthermore, NASinformation may be taken from the PCell.

The reconfiguration, addition and removal of SCells may be performed byRRC. At handover or reconfiguration with sync, Radio Resource Control(RRC) layer may also add, remove or reconfigure SCells for usage with atarget PCell. When adding a new SCell, dedicated RRC signaling may beused for sending all required system information of the SCell (e.g.,while in connected mode, UEs need not acquire broadcasted systeminformation directly from the SCells).

The systems and methods described herein may enhance the efficient useof radio resources in Carrier aggregation (CA) operation. Carrieraggregation refers to the concurrent utilization of more than onecomponent carrier (CC). In carrier aggregation, more than one cell maybe aggregated to a UE. In one example, carrier aggregation may be usedto increase the effective bandwidth available to a UE. In traditionalcarrier aggregation, a single base station is assumed to providemultiple serving cells for a UE. Even in scenarios where two or morecells may be aggregated (e.g., a macro cell aggregated with remote radiohead (RRH) cells) the cells may be controlled (e.g., scheduled) by asingle base station.

The systems and methods described herein may enhance the efficient useof radio resources in Carrier aggregation operation. Carrier aggregationrefers to the concurrent utilization of more than one component carrier(CC). In carrier aggregation, more than one cell may be aggregated to aUE. In one example, carrier aggregation may be used to increase theeffective bandwidth available to a UE. In traditional carrieraggregation, a single base station is assumed to provide multipleserving cells for a UE. Even in scenarios where two or more cells may beaggregated (e.g., a macro cell aggregated with remote radio head (RRH)cells) the cells may be controlled (e.g., scheduled) by a single basestation. However, in a small cell deployment scenario, each node (e.g.,base station, RRH, etc.) may have its own independent scheduler. Tomaximize the efficiency of radio resources utilization of both nodes, aUE may connect to two or more nodes that have different schedulers. Thesystems and methods described herein may enhance the efficient use ofradio resources in dual connectivity operation. A UE may be configuredmultiple groups of serving cells, where each group may have carrieraggregation operation (e.g., if the group includes more than one servingcell).

In Dual Connectivity (DC) the UE may be required to be capable of UL-CAwith simultaneous PUCCH/PUCCH and PUCCH/PUSCH transmissions acrosscell-groups (CGs). In a small cell deployment scenario, each node (e.g.,eNB, RRH, etc.) may have its own independent scheduler. To maximize theefficiency of radio resources utilization of both nodes, a UE mayconnect to two or more nodes that have different schedulers. A UE may beconfigured multiple groups of serving cells, where each group may havecarrier aggregation operation (e.g., if the group includes more than oneserving cell). A UE in RRC_CONNECTED may be configured with DualConnectivity or MR-DC, when configured with a Master and a SecondaryCell Group. A Cell Group (CG) may be a subset of the serving cells of aUE, configured with Dual Connectivity (DC) or MR-DC, i.e. a Master CellGroup (MCG) or a Secondary Cell Group (SCG). The Master Cell Group maybe a group of serving cells of a UE comprising of the PCell and zero ormore secondary cells. The Secondary Cell Group (SCG) may be a group ofsecondary cells of a UE, configured with DC or MR-DC, comprising of thePSCell and zero or more other secondary cells. A Primary Secondary Cell(PSCell) may be the SCG cell in which the UE is instructed to performrandom access when performing the SCG change procedure. “PSCell” may bealso called as a Primary SCG Cell. In Dual Connectivity or MR-DC, twoMAC entities may be configured in the UE: one for the MCG and one forthe SCG. Each MAC entity may be configured by RRC with a serving cellsupporting PUCCH transmission and contention based Random Access. In aMAC layer, the term Special Cell (SpCell) may refer to such cell,whereas the term SCell may refer to other serving cells. The term SpCelleither may refer to the PCell of the MCG or the PSCell of the SCGdepending on if the MAC entity is associated to the MCG or the SCG,respectively. A Timing Advance Group (TAG) containing the SpCell of aMAC entity may be referred to as primary TAG (pTAG), whereas the termsecondary TAG (sTAG) refers to other TAGs.

DC may be further enhanced to support Multi-RAT Dual Connectivity(MR-DC). MR-DC may be a generalization of the Intra-E-UTRA DualConnectivity (DC) described in 36.300, where a multiple Rx/Tx UE may beconfigured to utilize resources provided by two different nodesconnected via non-ideal backhaul, one providing E-UTRA access and theother one providing NR access. One node acts as a Mater Node (MN) andthe other as a Secondary Node (SN). The MN and SN are connected via anetwork interface and at least the MN is connected to the core network.In DC, a PSCell may be a primary secondary cell. In EN-DC, a PSCell maybe a primary SCG cell or SpCell of a secondary cell group.

E-UTRAN may support MR-DC via E-UTRA-NR Dual Connectivity (EN-DC), inwhich a UE is connected to one eNB that acts as a MN and one en-gNB thatacts as a SN. The en-gNB is a node providing NR user plane and controlplane protocol terminations towards the UE, and acting as Secondary Nodein EN-DC. The eNB is connected to the EPC via the S1 interface and tothe en-gNB via the X2 interface. The en-gNB might also be connected tothe EPC via the S1-U interface and other en-gNBs via the X2-U interface.

A timer is running once it is started, until it is stopped or until itexpires; otherwise it is not running. A timer can be started if it isnot running or restarted if it is running. A Timer may be always startedor restarted from its initial value.

For NR, a technology of aggregating NR carriers may be studied. Bothlower layer aggregation like Carrier Aggregation (CA) for LTE and upperlayer aggregation like DC are investigated. From layer 2/3 point ofview, aggregation of carriers with different numerologies may besupported in NR.

The main services and functions of the RRC sublayer may include thefollowing:

-   -   Broadcast of System Information related to Access Stratum (AS)        and Non Access Stratum (NAS);    -   Paging initiated by CN or RAN;    -   Establishment, maintenance and release of an RRC connection        between the UE and NR RAN including:    -   Addition, modification and release of carrier aggregation;    -   Addition, modification and release of Dual Connectivity in NR or        between LTE and NR;    -   Security functions including key management;    -   Establishment, configuration, maintenance and release of        signaling radio bearers and data radio bearers;    -   Mobility functions including:    -   Handover;    -   UE cell selection and reselection and control of cell selection        and reselection;    -   Context transfer at handover.    -   QoS management functions;    -   UE measurement reporting and control of the reporting;    -   NAS message transfer to/from NAS from/to UE.

Each MAC entity of a UE may be configured by RRC with a DiscontinuousReception (DRX) functionality that controls the UE's PDCCH monitoringactivity for the MAC entity's C-RNTI (Radio Network TemporaryIdentifier), CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI,TPC-PUSCH-RNTI, and TPC-SRS-RNTI. For scheduling at cell level, thefollowing identities are used:

-   -   C (Cell)-RNTI: unique UE identification used as an identifier of        the RRC Connection and for scheduling;    -   CS (Configured Scheduling)-RNTI: unique UE identification used        for Semi-Persistent Scheduling in the downlink;    -   INT-RNTI: identification of pre-emption in the downlink;    -   P-RNTI: identification of Paging and System Information change        notification in the downlink;    -   SI-RNTI: identification of Broadcast and System Information in        the downlink;    -   SP-CSI-RNTI: unique UE identification used for semi-persistent        CSI reporting on PUSCH;        For power and slot format control, the following identities are        used:    -   SFI-RNTI: identification of slot format;    -   TPC-PUCCH-RNTI: unique UE identification to control the power of        PUCCH;    -   TPC-PUSCH-RNTI: unique UE identification to control the power of        PUSCH;    -   TPC-SRS-RNTI: unique UE identification to control the power of        SRS;        During the random access procedure, the following identities are        also used:    -   RA-RNTI: identification of the Random Access Response in the        downlink;    -   Temporary C-RNTI: UE identification temporarily used for        scheduling during the random access procedure;    -   Random value for contention resolution: UE identification        temporarily used for contention resolution purposes during the        random access procedure.        For NR connected to 5GC, the following UE identities are used at        NG-RAN level:    -   I-RNTI: used to identify the UE context in RRC_INACTIVE.

The size of various fields in the time domain is expressed in time unitsT_(c)=1/(Δf_(max)·N_(f)) where Δf_(max)=480·10³ Hz and N_(f)=4096. Theconstant κ=T_(s)/T_(c)=64 where T_(s)=1/(Δf_(ref)·N_(f,ref)),Δf_(ref)=15·10³ Hz and N_(f,ref)=2048.

Multiple OFDM numerologies are supported as given by Table 4.2-1 of [TS38.211] where μ and the cyclic prefix for a bandwidth part are obtainedfrom the higher-layer parameter subcarrierSpacing and cyclicPrefix,respectively.

The size of various fields in the time domain may be expressed as anumber of time units T_(s)=1/(15000×2048) seconds. Downlink and uplinktransmissions are organized into frames withT_(f)=(Δf_(max)N_(f)/100)·T_(c)=10 ms duration, each consisting of tensubframes of T_(sf)=(Δf_(max)N_(f)/1000)·T_(c)=1 ms duration. The numberof consecutive OFDM symbols per subframe is N_(symb)^(subframe,μ)=N_(symb) ^(slot)N_(slot) ^(subframe,μ). Each frame isdivided into two equally-sized half-frames of five subframes each withhalf-frame 0 consisting of subframes 0-4 and half-frame 1 consisting ofsubframes 5-9.

For subcarrier spacing configuration μ, slots are numbered n_(s)^(μ)ϵ{0, . . . , N_(slot) ^(subframe,μ)−1} in increasing order within asubframe and n_(s,f) ^(μ)ϵ{0, . . . , N_(slot) ^(frame,μ)−1} inincreasing order within a frame. N_(slot) ^(subframe,μ) is the number ofslots per subframe for subcarrier spacing configuration μ. There areN_(symb) ^(slot) consecutive OFDM symbols in a slot where N_(symb)^(slot) depends on the cyclic prefix as given by Tables 4.3.2-1 and4.3.2-2 of [TS 38.211]. The start of slot n_(s) ^(μ) in a subframe isaligned in time with the start of OFDM symbol n_(s) ^(μ)N_(symb) ^(slot)in the same subframe.

OFDM symbols in a slot can be classified as ‘downlink’, ‘flexible’, or‘uplink’. Signaling of slot formats is described in subclause 11.1 of[TS 38.213].

In a slot in a downlink frame, the UE may assume that downlinktransmissions only occur in ‘downlink’ or ‘flexible’ symbols. In a slotin an uplink frame, the UE may only transmit in ‘uplink’ or ‘flexible’symbols.

Various examples of the systems and methods disclosed herein are nowdescribed with reference to the Figures, where like reference numbersmay indicate functionally similar elements. The systems and methods asgenerally described and illustrated in the Figures herein could bearranged and designed in a wide variety of different implementations.Thus, the following more detailed description of severalimplementations, as represented in the Figures, is not intended to limitscope, as claimed, but is merely representative of the systems andmethods.

FIG. 1 is a block diagram illustrating one configuration of one or morebase stations 160 (e.g., eNB, gNB) and one or more user equipments (UEs)102 in which systems and methods for search space configuration (orsearch for PDCCH candidates) and/or DCI size alignment may beimplemented. The one or more UEs 102 may communicate with one or morebase stations 160 using one or more antennas 122 a-n. For example, a UE102 transmits electromagnetic signals to the base station 160 andreceives electromagnetic signals from the base station 160 using the oneor more antennas 122 a-n. The base station 160 communicates with the UE102 using one or more antennas 180 a-n.

It should be noted that in some configurations, one or more of the UEs102 described herein may be implemented in a single device. For example,multiple UEs 102 may be combined into a single device in someimplementations. Additionally or alternatively, in some configurations,one or more of the base stations 160 described herein may be implementedin a single device. For example, multiple base stations 160 may becombined into a single device in some implementations. In the context ofFIG. 1, for instance, a single device may include one or more UEs 102 inaccordance with the systems and methods described herein. Additionallyor alternatively, one or more base stations 160 in accordance with thesystems and methods described herein may be implemented as a singledevice or multiple devices.

The UE 102 and the base station 160 may use one or more channels 119,121 to communicate with each other. For example, a UE 102 may transmitinformation or data to the base station 160 using one or more uplink(UL) channels 121 and signals. Examples of uplink channels 121 include aphysical uplink control channel (PUCCH) and a physical uplink sharedchannel (PUSCH), etc. Examples of uplink signals include a demodulationreference signal (DMRS) and a sounding reference signal (SRS), etc. Theone or more base stations 160 may also transmit information or data tothe one or more UEs 102 using one or more downlink (DL) channels 119 andsignals, for instance. Examples of downlink channels 119 include aPDCCH, a PDSCH, etc. Examples of downlink signals include a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),a cell-specific reference signal (CRS), a non-zero power channel stateinformation reference signal (NZP CSI-RS), and a zero power channelstate information reference signal (ZP CSI-RS), etc. Other kinds ofchannels or signals may be used.

Each of the one or more UEs 102 may include one or more transceivers118, one or more demodulators 114, one or more decoders 108, one or moreencoders 150, one or more modulators 154, one or more data buffers 104and one or more UE operations modules 124. For example, one or morereception and/or transmission paths may be implemented in the UE 102.For convenience, only a single transceiver 118, decoder 108, demodulator114, encoder 150 and modulator 154 are illustrated in the UE 102, thoughmultiple parallel elements (e.g., transceivers 118, decoders 108,demodulators 114, encoders 150 and modulators 154) may be implemented.

The transceiver 118 may include one or more receivers 120 and one ormore transmitters 158. The one or more receivers 120 may receive signals(e.g., downlink channels, downlink signals) from the base station 160using one or more antennas 122 a-n. For example, the receiver 120 mayreceive and downconvert signals to produce one or more received signals116. The one or more received signals 116 may be provided to ademodulator 114. The one or more transmitters 158 may transmit signals(e.g., uplink channels, uplink signals) to the base station 160 usingone or more antennas 122 a-n. For example, the one or more transmitters158 may upconvert and transmit one or more modulated signals 156.

The demodulator 114 may demodulate the one or more received signals 116to produce one or more demodulated signals 112. The one or moredemodulated signals 112 may be provided to the decoder 108. The UE 102may use the decoder 108 to decode signals. The decoder 108 may produceone or more decoded signals 106, 110. For example, a first UE-decodedsignal 106 may comprise received payload data, which may be stored in adata buffer 104. A second UE-decoded signal 110 may comprise overheaddata and/or control data. For example, the second UE-decoded signal 110may provide data that may be used by the UE operations module 124 toperform one or more operations.

As used herein, the term “module” may mean that a particular element orcomponent may be implemented in hardware, software or a combination ofhardware and software. However, it should be noted that any elementdenoted as a “module” herein may alternatively be implemented inhardware. For example, the UE operations module 124 may be implementedin hardware, software or a combination of both.

In general, the UE operations module 124 may enable the UE 102 tocommunicate with the one or more base stations 160. The UE operationsmodule 124 may include a UE RRC information configuration module 126.The UE operations module 124 may include a UE MCS control module 128. Insome implementations, the UE operations module 124 may include physical(PHY) entities, Medium Access Control (MAC) entities, Radio Link Control(RLC) entities, packet data convergence protocol (PDCP) entities, and anRadio Resource Control (RRC) entity. For example, the UE RRC informationconfiguration module 126 may process one or more RRC parameters for MCSconfiguration. The UE RRC information configuration module 126 mayprovide RRC configured MCS configuration and one or more predefined MCSindex tables. The UE decoder 108 may provide the DCI fields information(e.g. a MCS field, a HARQ process number field, a New data indicatorfield, a time domain resource assignment field, and/or a frequencydomain resource assignment field) to the UE MCS control module 128 afterprocessing a DCI format. The UE DCI control module 128 may furtherdetermine an MCS field size for a DCI format. The UE MCS control module128 may determine a modulation order and/or a target code rate based onthe processing output from the UE RRC information configuration module126 and the processing output from the UE decoder 108. The UE MCScontrol module 128 may further determine a TBS for transport block basedon the determined modulation order and the determined target code rate.

The UE operations module 124 may provide the benefit of receiving DCIformats efficiently and reliably by determining the bit width of the MCSfield for different DCI formats.

The UE operations module 124 may provide information 148 to the one ormore receivers 120. For example, the UE operations module 124 may informthe receiver(s) 120 when or when not to receive transmissions based onthe Radio Resource Control (RRC) message (e.g., broadcasted systeminformation, RRC reconfiguration message), MAC control element, and/oithe DCI (Downlink Control Information). The UE operations module 124 mayprovide information 148, including the PDCCH monitoring occasions andDCI format size, to the one or more receivers 120. The UE operationmodule 124 may inform the receiver(s) 120 when or where toreceive/monitor the PDCCH candidate for DCI formats with which DCI size.

The UE operations module 124 may provide information 138 to thedemodulator 114. For example, the UE operations module 124 may informthe demodulator 114 of a modulation pattern anticipated fortransmissions from the base station 160. For example, the UE operationsmodule 124 may inform the demodulator 114 of a determined modulationorder and/or a determined target code rate anticipated for transmissionsof a transport block from the base station 160.

The UE operations module 124 may provide information 136 to the decoder108. For example, the UE operations module 124 may inform the decoder108 of an anticipated encoding for transmissions from the base station160. For example, the UE operations module 124 may inform the modulator154 of a determined modulation order and/or a determined target coderate anticipated for transmissions of a transport block to the basestation 160.

The UE operations module 124 may provide information 142 to the encoder150. The information 142 may include data to be encoded and/orinstructions for encoding. For example, the UE operations module 124 mayinstruct the encoder 150 to encode transmission data 146 and/or otherinformation 142.

The encoder 150 may encode transmission data 146 and/or otherinformation 142 provided by the UE operations module 124. For example,encoding the data 146 and/or other information 142 may involve errordetection and/or correction coding, mapping data to space, time and/orfrequency resources for transmission, multiplexing, etc. The encoder 150may provide encoded data 152 to the modulator 154.

The UE operations module 124 may provide information 144 to themodulator 154. For example, the UE operations module 124 may inform themodulator 154 of a modulation type (e.g., constellation mapping) to beused for transmissions to the base station 160. The modulator 154 maymodulate the encoded data 152 to provide one or more modulated signals156 to the one or more transmitters 158.

The UE operations module 124 may provide information 140 to the one ormore transmitters 158. This information 140 may include instructions forthe one or more transmitters 158. For example, the UE operations module124 may instruct the one or more transmitters 158 when to transmit asignal to the base station 160. The one or more transmitters 158 mayupconvert and transmit the modulated signal(s) 156 to one or more basestations 160.

The base station 160 may include one or more transceivers 176, one ormore demodulators 172, one or more decoders 166, one or more encoders109, one or more modulators 113, one or more data buffers 162 and one ormore base station operations modules 182. For example, one or morereception and/or transmission paths may be implemented in a base station160. For convenience, only a single transceiver 176, decoder 166,demodulator 172, encoder 109 and modulator 113 are illustrated in thebase station 160, though multiple parallel elements (e.g., transceivers176, decoders 166, demodulators 172, encoders 109 and modulators 113)may be implemented.

The transceiver 176 may include one or more receivers 178 and one ormore transmitters 117. The one or more receivers 178 may receive signals(e.g., uplink channels, uplink signals) from the UE 102 using one ormore antennas 180 a-n. For example, the receiver 178 may receive anddownconvert signals to produce one or more received signals 174. The oneor more received signals 174 may be provided to a demodulator 172. Theone or more transmitters 117 may transmit signals (e.g., downlinkchannels, downlink signals) to the UE 102 using one or more antennas 180a-n. For example, the one or more transmitters 117 may upconvert andtransmit one or more modulated signals 115.

The demodulator 172 may demodulate the one or more received signals 174to produce one or more demodulated signals 170. The one or moredemodulated signals 170 may be provided to the decoder 166. The basestation 160 may use the decoder 166 to decode signals. The decoder 166may produce one or more decoded signals 164, 168. For example, a firstbase station-decoded signal 164 may comprise received payload data,which may be stored in a data buffer 162. A second base station-decodedsignal 168 may comprise overhead data and/or control data. For example,the second base station-decoded signal 168 may provide data (e.g., PUSCHtransmission data) that may be used by the base station operationsmodule 182 to perform one or more operations.

In general, the base station operations module 182 may enable the basestation 160 to communicate with the one or more UEs 102. The basestation operations module 182 may include a base station RRC informationconfiguration module 194. The base station operations module 182 mayinclude a base station MCS control module 196. The base stationoperations module 182 may include PHY entities, MAC entities, RLCentities, PDCP entities, and an RRC entity. For example, the basestation operation module 196 may determine, for UE(s), when and where tomonitor or search the configured PDCCH candidates for each search spaceset.

The base station RRC information configuration module 194 may generate,to a UE, one or more RRC parameters for MCS configurations based on thechannel state information reported by the UE. The base station MCScontrol module 196 may determine a modulation order and/or a target coderate and generate an MCS index in a MCS field to indicate the determinedmodulation order and/or the target code rate. The base station MCScontrol module 196 may further determine an MCS field size for a DCIformat for a UE 102. The base station MCS control module 196 may furtherdetermine a TBS for transport block based on the determined modulationorder and the determined target code rate.

The base station operations module 182 may provide the benefit oftransmitting DCI formats efficiently and reliably by determining the bitwidth of the MCS field for different DCI formats.

The base station operations module 182 may provide information 190 tothe one or more receivers 178. For example, the base station operationsmodule 182 may inform the receiver(s) 178 when or when not to receivetransmissions based on the RRC message (e.g., broadcasted systeminformation, RRC reconfiguration message), MAC control element, and/orthe DCI (Downlink Control Information).

The base station operations module 182 may provide information 188 tothe demodulator 172. For example, the base station operations module 182may inform the demodulator 172 of a modulation pattern anticipated fortransmissions from the UE(s) 102. For example, the base stationoperations module 182 may inform the demodulator 172 of a determinedmodulation order and/or a determined target code rate anticipated forPUSCH transmissions of a transport block from the UE 102.

The base station operations module 182 may provide information 186 tothe decoder 166. For example, the base station operations module 182 mayinform the decoder 166 of an anticipated encoding for transmissions fromthe UE(s) 102. For example, the base station operations module 182 mayinform the modulator 113 of a determined modulation order and/or adetermined target code rate anticipated for PDSCH transmissions of atransport block to the UE 102.

The base station operations module 182 may provide information 101 tothe encoder 109. The information 101 may include data to be encodedand/or instructions for encoding. For example, the base stationoperations module 182 may instruct the encoder 109 to encodetransmission data 105 and/or other information 101.

In general, the base station operations module 182 may enable the basestation 160 to communicate with one or more network nodes (e.g., a NGmobility management function, a NG core UP functions, a mobilitymanagement entity (MME), serving gateway (S-GW), gNBs). The base stationoperations module 182 may also generate a RRC reconfiguration message tobe signaled to the UE 102.

The encoder 109 may encode transmission data 105 and/or otherinformation 101 provided by the base station operations module 182. Forexample, encoding the data 105 and/or other information 101 may involveerror detection and/or correction coding, mapping data to space, timeand/or frequency resources for transmission, multiplexing, etc. Theencoder 109 may provide encoded data 111 to the modulator 113. Thetransmission data 105 may include network data to be relayed to the UE102.

The base station operations module 182 may provide information 103 tothe modulator 113. This information 103 may include instructions for themodulator 113. For example, the base station operations module 182 mayinform the modulator 113 of a modulation type (e.g., constellationmapping) to be used for transmissions to the UE(s) 102. The modulator113 may modulate the encoded data 111 to provide one or more modulatedsignals 115 to the one or more transmitters 117.

The base station operations module 182 may provide information 192 tothe one or more transmitters 117. This information 192 may includeinstructions for the one or more transmitters 117. For example, the basestation operations module 182 may instruct the one or more transmitters117 when to (or when not to) transmit a signal to the UE(s) 102. Thebase station operations module 182 may provide information 192,including the PDCCH monitoring occasions and DCI format size, to the oneor more transmitters 117. The base station operation module 182 mayinform the transmitter(s) 117 when or where to transmit the PDCCHcandidate for DCI formats with which DCI size. The one or moretransmitters 117 may upconvert and transmit the modulated signal(s) 115to one or more UEs 102.

It should be noted that one or more of the elements or parts thereofincluded in the base station(s) 160 and UE(s) 102 may be implemented inhardware. For example, one or more of these elements or parts thereofmay be implemented as a chip, circuitry or hardware components, etc. Itshould also be noted that one or more of the functions or methodsdescribed herein may be implemented in and/or performed using hardware.For example, one or more of the methods described herein may beimplemented in and/or realized using a chipset, an application-specificintegrated circuit (ASIC), a large-scale integrated circuit (LSI) orintegrated circuit, etc.

A base station may generate a RRC message including one or more RRCparameters, and transmit the RRC message to a UE. A UE may receive, froma base station, a RRC message including one or more RRC parameters. Theterm ‘RRC parameter(s)’ in the present disclosure may be alternativelyreferred to as ‘RRC information element(s)’. A RRC parameter may furtherinclude one or more RRC parameter(s). In the present disclosure, a RRCmessage may include system information. A RRC message may include one ormore RRC parameters. A RRC message may be sent on a broadcast controlchannel (BCCH) logical channel, a common control channel (CCCH) logicalchannel or a dedicated control channel (DCCH) logical channel.

Hereinafter, a description ‘a base station may configure a UE to’ mayalso imply/refer to ‘a base station may transmit, to a UE, an RRCmessage including one or more RRC parameters’. Additionally oralternatively, ‘RRC parameter configure a UE to’ may also refer to ‘abase station may transmit, to a UE, an RRC message including one or moreRRC parameters’. Additionally or alternatively, ‘a UE is configured to’may also refer to ‘a UE may receive, from a base station, an RRC messageincluding one or more RRC parameters’. Additionally or alternatively, ‘aRRC parameter is (not) provided’ may also refer to ‘a base station may(not) transmit, to a base station, an RRC message including a RRCparameters’.

A base station may transmit a RRC message including one or more RRCparameters related to BWP configuration to a UE. A UE may receive theRRC message including one or more RRC parameters related to BWPconfiguration from a base station. For each cell, the base station mayconfigure at least an initial DL BWP and one initial uplink bandwidthparts (initial UL BWP) to the UE. Furthermore, the base station mayconfigure additional UL and DL BWPs to the UE for a cell.

A RRC parameters initialDownlinkBWP may indicate the initial downlinkBWP (initial DL BWP) configuration for a serving cell (e.g., a SpCelland Scell). The base station may configure the RRC parameterlocationAndBandwidth included in the initialDownlinkBWP so that theinitial DL BWP contains the entire CORESET 0 of this serving cell in thefrequency domain. The locationAndBandwidth may be used to indicate thefrequency domain location and bandwidth of a BWP. A RRC parametersinitialUplinkBWP may indicate the initial uplink BWP (initial UL BWP)configuration for a serving cell (e.g., a SpCell and Scell). The basestation may transmit initialDownlinkBWP and/or initialUplinkBWP whichmay be included in SIB1, RRC parameter ServingCellConfigCommon, or RRCparameter ServingCellConfig to the UE.

SIB1, which is a cell-specific system information block(SystemInformationBlock, SIB), may contain information relevant whenevaluating if a UE is allowed to access a cell and define the schedulingof other system information. SIB1 may also contain radio resourceconfiguration information that is common for all UEs and barringinformation applied to the unified access control. The RRC parameterServingCellConfigCommon is used to configure cell specific parameters ofa UE's serving cell. The RRC parameter ServingCellConfig is used toconfigure (add or modify) the UE with a serving cell, which may be theSpCell or an SCell of an MCG or SCG. The RRC parameter ServingCellConfigherein are mostly UE specific but partly also cell specific.

The base station may configure the UE with a RRC parameter BWP-Downlinkand a RRC parameter BWP-Uplink. The RRC parameter BWP-Downlink can beused to configure an additional DL BWP. The RRC parameter BWP-Uplink canbe used to configure an additional UL BWP. The base station may transmitthe BWP-Downlink and the BWP-Uplink which may be included in RRCparameter ServingCellConfig to the UE.

If a UE is not configured (provided) initialDownlinkBWP from a basestation, an initial DL BWP is defined by a location and number ofcontiguous PRBs, starting from a PRB with the lowest index and ending ata PRB with the highest index among PRBs of a CORESET for Type0-PDCCH CSSset (i.e., CORESET 0), and a SCS and a cyclic prefix for PDCCH receptionin the CORESET for Type0-PDCCH CSS set. If a UE is configured (provided)initialDownlinkBWP from a base station, the initial DL BWP is providedby initialDownlinkBWP. If a UE is configured (provided) initialUplinkBWPfrom a base station, the initial UL BWP is provided by initialUplinkBWP.

The UE may be configured by the based station, at least one initial BWPand up to 4 additional BWP(s). One of the initial BWP and the configuredadditional BWP(s) may be activated as an active BWP. The UE may monitorDCI format, and/or receive PDSCH in the active DL BWP. The UE may notmonitor DCI format, and/or receive PDSCH in a DL BWP other than theactive DL BWP. The UE may transmit PUSCH and/or PUCCH in the active ULBWP. The UE may not transmit PUSCH and/or PUCCH in a BWP other than theactive UL BWP.

A base station may transmit a RRC message including one or more RRCparameters related to CORESET configuration. A base station mayconfigure a UE one or more CORESETs for each DL BWP in a serving cell.For example, a RRC parameter ControlResourceSetZero is used to configureCORESET 0 of an initial DL BWP. The RRC parameter ControlResourceSetZerocorresponds to 4 bits. The base station may transmitControlResourceSetZero, which may be included in MIB or RRC parameterServingCellConfigCommon, to the UE. MIB may include the systeminformation transmitted on BCH(PBCH). A RRC parameter related to initialDL BWP configuration may also include the RRC parameterControlResourceSetZero. A RRC parameter ControlResourceSet is used toconfigure a time and frequency CORESET other than CORESET 0. A RRCparameter ControlResourceSetId included in the ControlResourceSet isCORESET index, used to identify a CORESET within a serving cell.

A base station may transmit a RRC message including one or more RRCparameters related to search space configuration. A base station maydetermine one or more RRC parameter(s) related to search spaceconfiguration for a UE. A UE may receive, from a base station, a RRCmessage including one or more RRC parameters related to search spaceconfiguration. RRC parameter(s) related to search space configuration(e.g. SearchSpace, or SearchSpace-v16) defines how and where to searchfor PDCCH candidates. The RRC parameter(s) related to search spaceconfiguration (e.g. SearchSpace, SearchSpace-v16) may have differentinformation element structures. ‘search/monitor for PDCCH candidate fora DCI format’ may also refer to ‘monitor/search for a DCI format’ forshort.

FIG. 2 is a diagram illustrating a RRC parameter (RRC information)SearchSpace with an information element structure A 200.

A RRC parameter SearchSpace is related to search space configuration.The RRC parameters search space may include a plurality of RRCparameters as like, searchSpaceId, controlResourceSetId,monitoringSlotPeriodicityAndOffset, duration,monitoringSymbolsWithinSlot, nrofCandidates, searchSpaceType. Some ofthe above-mentioned RRC parameters may be present or absent in the RRCparameters SearchSpace. Namely, the RRC parameter SearchSpace mayinclude all the above-mentioned RRC parameters. Namely, the RRCparameter SearchSpace may include one or more of the above-mentioned RRCparameters. If some of the parameters are absent in the RRC parameterSearchSpace, the UE 102 may apply a default value for each of thoseparameters.

Here, the RRC parameter searchSpaceId is an identity or an index of asearch space. The RRC parameter searchSpaceId is used to identify asearch space. Or rather, the RRC parameter serchSpaceId provide a searchspace set index s, 0<=s<40. Then a search space set s hereinafter mayrefer to a search space set identified by index s indicated by RRCparameter searchSpaceId. The RRC parameter controlResourceSetId concernsan identity of a CORESET, used to identify a CORESET. The RRC parametercontrolResourceSetId indicates an association between the search space sand the CORESET identified by controlResourceSetId. The RRC parametercontrolResourceSetId indicates a CORESET applicable for the searchspace. CORESET p hereinafter may refer to a CORESET identified by indexp indicated by RRC parameter controlResourceSetId. Each search space setis associated with one CORESET. The RRC parametermonitoringSlotPeriodicityAndOffset is used to indicate slots for PDCCHmonitoring configured as periodicity and offset. Specifically, the RRCparameter monitoringSlotPeriodicityAndOffset indicates a PDCCHmonitoring periodicity of k_(s) slots and a PDCCH monitoring offset ofo_(s) slots. A UE can determine which slot is configured for PDCCHmonitoring according to the RRC parametermonitoringSlotPeriodicityAndOffset. The RRC parametermonitoringSymbolsWithinSlot is used to indicate a first symbol(s) forPDCCH monitoring in the slots configured for PDCCH monitoring. That is,the parameter monitoringSymbolsWithinSlot provides a PDCCH monitoringpattern within a slot, indicating first symbol(s) of the CORESET withina slot (configured slot) for PDCCH monitoring. The RRC parameterduration indicates a number of consecutive slots T_(s) that the searchspace lasts (or exists) in every occasion (PDCCH occasion, PDCCHmonitoring occasion).

The RRC parameter may include aggregationLevel1, aggregationLevel2,aggregationLevel4, aggregationLevel8, aggregationLevel16. The RRCparameter nrofCandidates may provide a number of PDCCH candidates perCCE aggregation level L by aggregationLevel1, aggregationLevel2,aggregationLevel4, aggregationLevel8, and aggregationLevel16, for CCEaggregation level 1, CCE aggregation level 2, CCE aggregation level 4,for CCE aggregation level 8, and CCE aggregation level 16, respectively.In other words, the value L can be set to either one in the set {1, 2,4, 8, 16}. The number of PDCCH candidates per CCE aggregation level Lcan be configured as 0, 1, 2, 3, 4, 5, 6, or 8. For example, in a casethe number of PDCCH candidates per CCE aggregation level L is configuredas 0, the UE may not search for PDCCH candidates for CCE aggregation L.That is, in this case, the UE may not monitor PDCCH candidates for CCEaggregation L of a search space set s. For example, the number of PDCCHcandidates per CCE aggregation level L is configured as 4, the UE maymonitor 4 PDCCH candidates for CCE aggregation level L of a search spaceset s.

The RRC parameter searchSpaceType is used to indicate that the searchspace set s is either a CSS set or a USS set. The RRC parametersearchSpaceType may include either a common or a ue-Specific. The RRCparameter common configure the search space set s as a CSS set and DCIformat to monitor. The RRC parameter ue-Specific configures the searchspace set s as a USS set. The RRC parameter ue-Specific may includedci-Formats. The RRC parameter dci-Formats indicates to monitor PDCCHcandidates either for DCI format 0_0 and DCI format 1_0, or for DCIformat 0_1 and DCI format 1_1 in search space set s. That is, the RRCparameter searchSpaceType indicates whether the search space set s is aCSS set or a USS set as well as DCI formats to monitor for.

A USS at CCE aggregation level L is defined by a set of PDCCH candidatesfor CCE aggregation L. A USS set may be constructed by a plurality ofUSS corresponding to respective CCE aggregation level L. A USS set mayinclude one or more USS(s) corresponding to respective CCE aggregationlevel L. A CSS at CCE aggregation level L is defined by a set of PDCCHcandidates for CCE aggregation L. A CSS set may be constructed by aplurality of USS corresponding to respective CCE aggregation level L. ACSS set may include one or more CSS(s) corresponding to respective CCEaggregation level L.

As above-mentioned, the RRC parameter SearchSpace with informationelement structure A is capable of indicating that the search space set sis a CSS (e.g. a CSS set) or a USS (e.g. a USS set). A base station mayconfigure a UE to whether monitor PDCCH candidates for DCI format 0_0and DCI format 1_0, or for DCI format 0_1 and DCI format 1_1 in a USSset via the RRC parameter SearchSpace with information element structureA. That is, the base station may not configure a UE to monitor PDCCHcandidates for a different DCI format(s) other than the existing DCIformat(s) {DCI format 0_0, DCI format 1_0, DCI format 0_1, DCI format1_1} in the USS set via the RRC parameter SearchSpace with informationelement structure A. In other words, the UE may, based on the receivedRRC parameter SearchSpace from the base station, monitor PDCCHcandidates either for DCI format 0_0 and DCI format 1_0, or for DCIformat 0_1 and DCI format 1_1 in a USS. The UE may be not be configuredto monitor PDCCH candidates for a different DCI format(s) other than theexisting DCI format(s) {DCI format 0_0, DCI format 1_0, DCI format 0_1,DCI format 1_1} in the USS.

Communication with new service traffic type like (but not limited to)URLLC may require new DCI format(s) design other than the existing DCIformats. For example, some new fields may be introduced in a new DCIformat to implement different communication features. For example, somefields included in the existing DCI formats may be not necessary anymore to adapt different communication features. In order to implementcommunication feature with different service traffic types, differentDCI formats may be generated according to different service traffictypes. Introduction of new DCI format(s) other than the existing DCIformats would be beneficial and efficient for communication with a newservice traffic type like URLLC between based station(s) and UE(s).Hence, the RRC parameter SearchSpace with current information elementstructure A may be problematic, which is incapable of indicating a newDCI format. It would be beneficial to introduce a RRC parameter relatedto search space configuration with a new information element structureso that the base station may indicate/configure a UE to monitor PDCCHcandidates for new DCI format(s) other than the existing DCI formats ina USS.

FIG. 3 is a diagram illustrating a RRC parameter SearchSpace-v16 with aninformation element structure B 300.

The RRC parameter SearchSpace-v16 with an information element structureB is related to search space configuration. As one example 302, the RRCparameter SearchSpace-v16 with an information element structure B mayinclude a plurality of RRC parameters as like, searchSpaceId,controlResourceSetId, monitoringSlotPeriodicityAndOffset, duration,monitoringSymbolsWithinSlot, nrofCandidates, searchSpaceType. Some ofthe above-mentioned RRC parameters may be present or absent in the RRCparameters SearchSpace-v16. The searchSpaceType-v16 included in RRCparameter SearchSpace-v16 with an information element structure B may bedifferent from the searchSpaceType included in the RRC parameterSearchSpace with information element structure A. ThesearchSpaceType-v16 may only indicate that the search space set s is aUSS set. The searchSpaceType-v16 may not be used to indicate that thesearch space set s is a CSS set. The RRC parameter searchSpaceType-v16may include ue-Specific. The RRC parameter searchSpaceType-v16 may notinclude common. The RRC parameter searchSpaceType-v16 may also includedci-Format-v16. The dci-Format-v16 may be used to indicate whether theUE monitors PDCCH candidates in the USS for DCI formats 0_0 and 10, orfor DCI formats 0_2 and 1_2. That is, the dci-Format-v16 may be used toindicate which for DCI formats 0_0 and 1_0, or for DCI formats 0_2 and1_2, the UE monitors PDCCH candidates in the USS. Additionally oralternatively, the dci-Format-v16 may be used to indicate which for DCIformats 0_0 and 1_0, or for DCI formats 0_1 and 1_1, or for DCI formats0_2 and 1_2, the UE monitors PDCCH candidates in the USS. Additionallyor alternatively, the dci-Format-v16 may be used to indicate which forDCI formats 0_2, or for DCI format 1_2, the UE monitors PDCCH candidatesin the USS. Additionally or alternatively, the RRC parametersearchSpaceType-v16 may not include a RRC parameter (e.g.dci-Format-v16). That is, if a USS is configured/provided by the RRCparameter SearchSpace-v16, the UE may implicitly determine to monitorPDCCH candidates in the USS for DCI formats 02 and/or 12.

As one example 304, the RRC parameter SearchSpace-v16 with aninformation element structure B may include a RRC parameterue-Specific-v16. The ue-Specific-v16 is used to configure the searchspace as a USS set. The RRC parameter SearchSpace-v16 with aninformation element structure B may not include a RRC parameter commonwhich is used to configure a search space set s as a CSS set. The RRCparameter ue-Specific-v16 may include a RRC parameterformats0-2-And-1-2. The RRC parameter formats0-2-And-1-2 may configure aUE to monitor PDCCH candidates in the USS set for DCI format 0_2 and DCIformat 1_2. Additionally or alternatively, the RRC parameterformats0-2-And-1-2 may configure a UE to monitor PDCCH candidates in theUSS set for DCI format 0_2 or for DCI format 12.

As described in both 302 and 304, the RRC parameter SearchSpace-v16 withan information element structure B is not capable of indicating that thesearch space set s is a CSS (e.g. a CSS set). The RRC parameterSearchSpace-v16 with an information element structure B is capable ofindicating that the search space set s is a USS. As described in 202,the RRC parameter SearchSpace with an information element structure A iscapable of indicating that the search space set s is a CSS (e.g. a CSSset) or a USS (e.g. a USS set).

FIG. 4 is a diagram illustrating a RRC parameter SearchSpace-v16 with aninformation element structure C 400.

The RRC parameter SearchSpace-v16 with an information element structureC is related to search space configuration. As depicted in 402, the RRCparameter SearchSpace-v16 with an information element structure C mayinclude a RRC parameter searchSpaceType-v16. The RRC parameters common,ue-Specific, ue-Specific-v16 included in searchSpaceType-v16, may beused to indicate that the search space set s is a CSS set, a USS set A,or a USS set B, respectively. The USS set A (ue-Specific) may indicatewhether a UE monitor for DCI formats 0_0 and 1_0 or for DCI formats 0_1and 1_1 in the USS set A. A RRC parameter nrofCandidates-v16, which maybe included in SearchSpace-v16 but may not be included in ue-Specific,may provide a number of PDCCH candidates per CCE aggregation level L forDCI formats 0_0 and 1_0 or for DCI formats 0_1 and 1_1. The USS set B(ue-Specific-v16) may indicate that a UE may monitor for DCI formats 0_2and 1_2 in the USS set. Furthermore, the ue-Specific-v16 may furtherinclude a RRC parameter nrofCandidates-v16 which may provide a number ofPDCCH candidates per CCE aggregation level L for DCI formats 0_2 and1_2. Hence, The RRC parameter SearchSpace-v16 with an informationelement structure C is capable of indicating that a search space set isa CSS set, a first USS set (USS set A), or a second USS set (USS set B).The CSS set (common) may indicate that a UE may monitor for DCI formats00 and 10 in the CSS set.

According to another example, a RRC parameter searchSpaceType-v16 in 402may include either a common or a ue-Specific and but may not includeue-Specific-v16. In this case, the RRC parameter dci-Formats included inue-Specific may indicate whether a UE may monitor PDCCH candidates forDCI format 0_0 and DCI format 1_0, or for DCI format 0_1 and DCI format1_1, or for DCI format 0_2 and DCI format 12 in the USS set.Furthermore, in a case that dci-Formats indicates a UE to monitor PDCCHcandidates for DCI format 0_2 and DCI format 1_2, the dci-Formats mayfurther include a RRC parameter nrofCandidates-v16 which may provide anumber of PDCCH candidates per CCE aggregation level L for the DCIformat 0_2 and DCI format 12. Otherwise, the RRC parameternrofCandidates-v16 may be absent in the dci-Formats.

The RRC parameters as like searchSpaceId, controlResourceSetId,monitoringSlotPeriodicityAndOffset, duration,monitoringSymbolsWithinSlot, nrofCandidates in 302, 304, and 402 mayhave same usage as those in 202. Some of the above-mentioned RRCparameters may be present or absent in the RRC parametersSearchSpace-v16.

A PDCCH may consist of one or more control channel elements (CCEs). ACCE may consist of 6 resource element groups (REGs). A REG may equal oneresource block during one OFDM symbol. The PDCCH is used fortransmitting Downlink Control Information (DCI) in a case of downlinkradio communication (radio communication from the base station to theUE). Here, one or more DCIs (may be referred to as DCI formats) aredefined for transmission of downlink control information. Informationbits are mapped to one or more fields defined in a DCI format. A UE maymonitor a set of PDCCH candidates in one or more control Resource set(CORESET) on an active DL BWP on an activated cell. Monitoring meansdecoding each PDCCH candidate according to the monitored DCI formats.

A set of PDCCH candidates for a UE to monitor is defined in terms ofPDCCH search space sets. A PDCCH candidate for a search space sets maycorrespond to a set of CCEs in a CORESET associated with the searchspace set s. In the present disclosure, the term “PDCCH search spacesets” may also refer to “PDCCH search space”. In the present disclosure,the term “search space sets” may also refer to “search space”. A UEmonitors PDCCH candidates in one or more of search space sets. A searchspace sets can be a common search space (CSS) set or a UE-specificsearch space (USS) set. In some implementations, a CSS set may beshared/configured among multiple UEs. The multiple UEs may search PDCCHcandidates in the CSS set. In some implementations, a USS set isconfigured for a specific UE. The UE may search one or more PDCCHcandidates in the USS set. In some implementations, a USS set may be atleast derived from a value of C-RNTI addressed to a UE. In other words,a UE can determine the CCE indexes for aggregation level L correspondingto PDCCH candidates of a USS for a USS set based on the value of C-RNTIaddressed to the UE. The UE can determine the CCE indexes foraggregation level L corresponding to PDCCH candidates of a CSS for a CSSset without the value of C-RNTI addressed to the UE.

A UE may monitor a set of PDCCH candidates in one or more of thefollowing search space sets

-   -   a Type0-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or        by searchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero        in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a        SI-RNTI on the primary cell of the MCG    -   a Type0A-PDCCH CSS set configured by        searchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a        DCI format with CRC scrambled by a SI-RNTI on the primary cell        of the MCG    -   a Type1-PDCCH CSS set configured by ra-SearchSpace in        PDCCH-ConfigCommon for a DCI format with CRC scrambled by a        RA-RNTI or a TC-RNTI on the primary cell    -   a Type2-PDCCH CSS set configured by pagingSearchSpace in        PDCCH-ConfigCommon for a DCI format with CRC scrambled by a        P-RNTI on the primary cell of the MCG    -   a Type3-PDCCH CSS set configured by SearchSpace in PDCCH-Config        with searchSpaceType=common for DCI formats with CRC scrambled        by INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, or        TPC-SRS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI,        or CS-RNTI(s), and    -   a USS set configured by SearchSpace in PDCCH-Config with        searchSpaceType=ue-Specific for DCI formats with CRC scrambled        by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, or CS-RNTI(s).

A UE may monitor a set of PDCCH candidates in the configured monitoringoccasions in one or more configured control resource sets (CORESETs)according to the corresponding search space configurations.

DCI formats (or DCI) may be clarified as DCI format 0_0, DCI format 1_0,DCI format 1_1 (DCI format C), DCI format 0_1 (DCI format D), DCI format1_2 (DCI format E), DCI format 0_2 (DCI format F), and so on.

DCI format 1_0 may be used for the scheduling of PDSCH in one cell. A UEmay monitor the DCI format 1_0 with CRC scrambled by C-RNTI or CS-RNTIor MCS-C-RNTI or P-RNTI or SI-RNTI or RA-RNTI or TC-RNTI. The UE maymonitor the DCI format 0_0 in a CSS (e.g. a CSS set) or a USS (e.g. aUSS set). DCI format 0_0 may be used for the scheduling of PUSCH in onecell. A UE may monitor the DCI format 0_0 with CRC scrambled by C-RNTIor CS-RNTI or MCS-C-RNTI or TC-RNTI. The UE may monitor the DCI format0_0 in a CSS (e.g. a CSS set) or a USS (e.g. a USS set).

Furthermore, the DCI format 1_0 monitored in a CSS may be used for thescheduling of broadcasting data. The DCI format 1_0 monitored in a CSSmay be also used for the scheduling of UE-specific data. The DCI format0_0 may be used for the scheduling of UE-specific data.

DCI format 0_0 may include predefined fields with fixed bits except forthe ‘Frequency domain resource assignment’ field. The fields for DCIformat 0_0 sequentially correspond to, ‘Identifier for DCI formats’field with 1 bit, ‘Frequency domain resource assignment’ field, ‘Timedomain resource assignment’ field with 4 bits, ‘Frequency hopping flag’field with 1 bit, ‘Modulation and coding scheme’ field with 5 bits, ‘Newdata indicator’ field with 1 bit, ‘Redundancy version’ field with 2bits, ‘HARQ process number’ field with 4 bits, ‘TPC command forscheduled PUSCH’ field with 2 bits, ‘UL/SUL indicator’ field with 1 bit.The size of the ‘Frequency domain resource assignment’ field for DCIformat 0_0 may be determined based on a size of a UL bandwidth part. Forexample, the size of the ‘Frequency domain resource assignment’ fieldmay be determined based on Formula (1) ceil(log₂(N_(RB) ^(UL,BWP)(N_(RB) ^(UL,BWP)+1)/2)) wherein the N_(RB) ^(UL,BWP) is a size of ULbandwidth part. The function ceil(x) means the function that takes asinput a real number x and gives as output the least integer greater thanor equal to x.

DCI format 1_0 may include predefined fields with fixed bits except forthe ‘Frequency domain resource assignment’ field. The fields for DCIformat 1_0 sequentially correspond to, ‘Identifier for DCI formats’field with 1 bit, ‘Frequency domain resource assignment’ field, ‘Timedomain resource assignment’ field with 4 bits, ‘VRB-to-PRB mapping’field with 1 bit, ‘Modulation and coding scheme’ field with 5 bits, ‘Newdata indicator’ field with 1 bit, ‘Redundancy version’ field with 2bits, ‘HARQ process number’ field with 4 bits, ‘Downlink assignmentindex’ field with 2 bits, ‘TPC command for scheduled PUCCH’ field with 2bits, ‘PUCCH resource indicator’ field with 3 bits,‘PDSCH-to-HARQ_feedback timing indicator’ field with 3 bits. The size ofthe ‘Frequency domain resource assignment’ field for DCI format 1_0 maybe determined based on a size of a DL bandwidth part, and/or a size ofCORESET 0. For example, the size of the ‘Frequency domain resourceassignment’ field may be determined based on Formula (2)ceil(log₂(N_(RB) ^(DL,BWP) (N_(RB) ^(DL,BWP)+1)/2)) wherein the N_(RB)^(DL,BWP) is a size of UL bandwidth part or a size of CORESET 0.

DCI format 0_0 and DCI format 1_0 can be configured to be monitored in aCSS (e.g. a CSS set) or a USS (e.g. a USS set). The DCI format 0_0 andDCI format 1_0 being monitored in a CSS may be also called as defaultDCI formats. In other words, the DCI format 0_0 and DCI format 1_0 beingmonitored in a USS may not be called as default DCI formats.

DCI format C may refer to DCI format (e.g. DCI format 1_1) monitored ina USS. DCI format C (DCI format 1_1) may be used for the scheduling ofPDSCH in one cell. DCI format 1_1 may schedule up to two transportblocks for one PDSCH. A UE may monitor the DCI format 1_1 with CRCscrambled by C-RNTI or CS-RNTI or MCS-C-RNTI. The UE may monitor the DCIformat 1_1 in a USS The UE may not monitor the DCI format 1_1 in a CSS.DCI format 1_1 may be used for the scheduling of UE-specific data. DCIformat 1_1 may include a plurality of fields with fixed bits and aplurality of fields with variable bits. The size of fields with variablebits are determined based on corresponding RRC configuration.

DCI format D may refer to DCI format (e.g. DCI format 0_1) monitored ina USS. DCI format 0_1 may be used for the scheduling of PUSCH in onecell. DCI format 0_1 may schedule up to two transport blocks for onePUSCH. A UE may monitor the DCI format 0_1 with CRC scrambled by C-RNTIor CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI. The UE may monitor the DCIformat 0_1 in a USS. The UE may not monitor the DCI format 0_1 in a CSS.DCI format 0_1 may be used for the scheduling of UE-specific data. DCIformat 0_1 may include a plurality of fields with fixed bits and aplurality of fields with variable bits. The size of fields with variablebits are determined based on corresponding RRC configuration.

DCI format E may refer to DCI format (e.g. DCI format 1_2) monitored ina USS. DCI format 1_2 may be used for the scheduling of PDSCH in onecell. DCI format 1_2 may schedule one transport block for one PDSCH. AUE may monitor the DCI format 1_2 in a USS. The UE may not monitor theDCI format 1_2 in a CSS. DCI format 1_2 may be used for the schedulingof UE-specific data. DCI format 1_2 may include a plurality of fieldswith fixed bits and a plurality of fields with variable bits. The sizeof fields with variable bits are determined based on corresponding RRCconfiguration. DCI format 1_2 may not consist of some fields (e.g. ‘CBGtransmission information’ field), which may be present in DCI format1_1.

DCI format F may refer to DCI format (e.g. DCI format 0_2) monitored ina USS. DCI format 0_2 may be used for the scheduling of PUSCH in onecell. DCI format 0_2 may schedule one transport block for one PUSCH.Additionally, UE may monitor the DCI format F with CRC scrambled byC-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI. The UE may monitor theDCI format 0_2 in a USS. The UE may not monitor the DCI format 0_2 in aCSS. DCI format 0_2 may be used for the scheduling of UE-specific data.DCI format 0_2 may include a plurality of fields with fixed bits and aplurality of fields with variable bits. The size of fields with variablebits are determined based on corresponding RRC configuration. DCI format0_2 may not consist of some fields (e.g. ‘CBG transmission information’field), which may be present in DCI format 0_1.

DCI formats C and D may be used to schedule traffic service data (e.g.eMBB). For example, DCI format C may be used to schedule a first PDSCHtransmitting eMBB data. DCI format D may be used to schedule a firstPUSCH transmitting eMBB data.

DCI formats E and F may be used to schedule traffic service data (e.g.URLLC). For example, DCI format E may be used to schedule a second PDSCHtransmitting URLLC data. DCI format F may be used to schedule a secondPUSCH transmitting URLLC data. Additionally or alternatively, DCIformats E and F may be DCI formats with CRC scrambled by a second RNTIwhich is different from a first RNTI(s) for DCI formats C and D. Thatis, DCI format E may be a DCI format 1_1 with CRC scrambled by a secondRNTI. DCI format C may be a DCI format 1_1 with CRC scrambled by a firstRNTI (e.g. C-RNTI). DCI format F may be a DCI format 0_1 with CRCscrambled by a second RNTI. DCI format D may be a DCI format 0_1 withCRC scrambled by a first RNTI (e.g. C-RNTI).

Additionally or alternatively, DCI formats C and D may be transmitted ina first CORESET, while DCI formats E and F may be transmitted in asecond CORESET which is different from the first CORESET. A RRCparameter, which is used to identity the DCI formats configured bydci-Formats are DCI formats C and D or DCI formats E and F, may bepresent (or set to ‘enable’) in a CORESET configuration for the secondCORESET. The RRC parameter may be absent (or set to ‘disable’) in aCORESET configuration for the first CORESET. As mentioned above, aCORESET is associated with a search space set s, in which DCI formatsare configured to monitor. For example, dci-Formats may indicate tomonitor PDCCH candidates for DCI format 0_1 and DCI format 1_1 in searchspace set s. If the RRC parameter is absent in the CORESET configurationfor the associated CORESET, the DCI format 0_1 and DCI format 1_1monitored in the CORESET may refer to DCI format C and D. If the RRCparameter is present in the CORESET configuration for the associatedCORESET, the DCI format 0_1 and DCI format 1_1 monitored in the CORESETmay refer to DCI format E and F. That is, the DCI format C and D may bethe DCI format 0_1 and DCI format 1_1 monitored in the first CORESET.The DCI format C and D may be the DCI format 0_1 and DCI format 1_1monitored in the second CORESET.

Additionally or alternatively, DCI formats C and D may be transmitted ina first search space set s, while DCI formats E and F may be transmittedin a second search space set s which is different from the first searchspace set s. A RRC parameter, which is used to identity the DCI formatsconfigured by dci-Formats are DCI formats C and D or DCI formats E andF, may be present (or set to ‘enable’) in ue-Specific (SearchSpace, orSearchSpace-v16) for the second search space set s. The RRC parametermay be absent (or set to ‘disable’) in ue-Specific (SearchSpace, orSearchSpace-v16) for the first search space set s. For example,dci-Formats may indicate to monitor PDCCH candidates for DCI format 01and DCI format 1_1 in search space set s. If the RRC parameter is absentin ue-Specific for the search space set s, the DCI format 0_1 and DCIformat 1_1 monitored in the search space set s may refer to DCI format Cand D. If the RRC parameter is present in ue-Specific for the searchspace set s, the DCI format 0_1 and DCI format 1_1 monitored in thesearch space set s may refer to DCI format E and F. That is, the DCIformat C and D may be the DCI format 0_1 and DCI format 1_1 configuredin the first search space set s. The DCI format E and F may be the DCIformat 0_1 and DCI format 1_1 configured in the second search space sets.

DCI (format) used for the downlink scheduling is also referred to asdownlink grant or downlink assignment. DCI (format) used for the uplinkscheduling is also referred to as uplink grant or uplink assignment.

Different DCI formats (DCI) may consist of different fields. The fieldsdefined in the DCI formats maybe mapped to a number of information bits.Each field may be mapped to 0, 1, or more bits of the information bits.That is, a field may include 0, 1, or more bits of the information bits.In a case that a field is mapped to 0 bit, the UE may determine thefield is absent in the DCI format. In other words, if a field is mappedto 1, or more bits, the UE may determine the field is present in the DCIformat. Furthermore, a field may also include 0, 1, or more zero-paddingbit(s). If the number of the information bits in DCI format is less than12 bits, zero may be appended to the DCI format until the payload sizeequals 12. A DCI format may include a plurality of fields and 0, 1, ormore zero-padding bit(s). The payload size of a DCI format may be equalto a quantity of the information bits and zero-padding bits(s). Thenumber of the zero-padding bits may be 0, 1, or more bits for a DCIformat. Herein, the size of a DCI format (DCI format size, DCI size) mayrefer to the payload size of the DCI format. Alternatively, oradditionally, the size of a DCI format may also refer to the size of theinformation bits of the DCI format.

A base station may transmit, to a UE, a PDCCH with a DCI (a schedulingDCI, a DCI format). The scheduling DCI may be used to schedule a PDSCHwith a transport block. In other words, the base station may furthertransmit, to the UE, a transport block in a PDSCH scheduled by a DCItransported in a PDCCH. A UE may receive, from a base station, a DCI (ascheduling DCI) in the PDCCH and may further receive a transport blockin a PDSCH scheduled by the DCI transported in the PDCCH.

A base station may transmit, to a UE, a PDCCH with a DCI (a schedulingDCI, a DCI format). The scheduling DCI may be used to schedule a PUSCHwith a transport block. A UE may receive, from a base station, a DCI (ascheduling DCI) in the PDCCH and may further transmit, to a basestation, a transport block in a PUSCH scheduled by the DCI transportedin the PDCCH. The base station may receive, from the UE, a transportblock in a PUSCH scheduled by the DCI transported in the PDCCH.

FIG. 5 is a diagram illustrating one example of MCS index table 500.

FIG. 5 is one example of a predefined MCS index table 500 which includes32 entries (elements, rows) of MCS configuration. The predefined MCSindex table 500 may be provided in specifications and can be used forPDSCH and/or PUSCH. Each entry of MCS configuration corresponds to anMCS index identified by I_(MCS). The value of I_(MCS) is in a range of{0, . . . , 31}. Each entry in the table may contain an MCS indexI_(MCS), a modulation order Q_(m), a target code rate R, and a value forspectral efficiency. A UE may be provided with more than one predefinedMCS index tables in the specifications. That is, specifications maypredefine more than one MCS index tables. The predefined MCS indextables may be used for PDSCH and PUSCH. These predefined MCS indextables are known to the UEs and the base stations. A base station mayinstruct a UE to use which MCS index table from the more than one MCSindex tables. In other words, the base station may transmit, to the UE,a RRC parameter included in a RRC message to indicate which MCS indextable the UE use for PDSCH. The UE may determine to use which MCS indextable for PDSCH based on the received RRC parameter from the basestation. Furthermore, the base station may transmit, to the UE, anotherRRC parameter included in the same RRC message to indicate which MCSindex table the UE use for PUSCH. The UE may determine to use which MCSindex table for PUSCH based on the received another RRC parameter. TheMCS index table used for PDSCH may be same with the MCS index table usedfor PUSCH. The MCS index table used for PDSCH may be different from theMCS index table used for PUSCH. A predefined MCS index table hereinaftermay refer to a MCS index table which is indicated by the RRC parameter.

When a base station plans to indicate a UE to receive a transport blockin a PDSCH or to transmit a transport block in a PUSCH, the base stationmay determine a modulation order Q_(m), target code rate R, spectralefficiency for the PDSCH or the PUSCH at least based on the channelstate information reported by the UE and the available time andfrequency resource. In other words, the base station may determine amodulation order Q_(m), target code rate R, spectral efficiency from adetermined MCS index table and then may generate a ‘Modulation andcoding scheme’ field. Then the base station may transmit, to the UE, aDCI format including the generated ‘Modulation and coding scheme’ fieldin a PDCCH. The UE may upon detection of a PDCCH with the DCI format,may read the ‘Modulation and coding scheme’ field in the scheduling DCIformat.

For a PDSCH (or a PUSCH) scheduled by a DCI format, a UE may read the‘Modulation and coding scheme’ field in the scheduling DCI format todetermine a modulation order Q_(m), target code rate R for the PDSCH (orthe PUSCH) based on the determined MCS index table. For example, for aUE, the MCS index table may be determined as MCS index table 500. If‘Modulation and coding scheme’ field in the scheduling DCI indicatesvalue 0, the UE may use an entry with I_(MCS)=0 in the MCS index table500 to determine the modulation Q_(m) and target code rate R for thePDSCH (or the PUSCH) scheduled by the scheduling DCI. If ‘Modulation andcoding scheme’ field in the scheduling DCI indicates value 10, the UEmay use an entry with I_(MCS)=10 in the MCS index table 500 to determinethe modulation Q_(m) and target code rate R for the PDSCH (or the PUSCH)scheduled by the scheduling DCI. For a PDSCH (or the PUSCH) scheduled bya DCI format, which I_(MCS) is used is according to the value of the‘Modulation and coding scheme’ field.

After determining the Q_(m) and R, the UE (or the base station) may atleast use the determined Q_(m) and R with other information to furtherdetermine the transport block size (TBS) for the transport block in thePDSCH or the PUSCH. The other information may be provided by thescheduling DCI and the RRC parameters. For example, the otherinformation may include the information as like the number of layers(u), the total number of allocated resource blocks of the PDSCH (or thePUSCH), the total number of allocated symbols of the PDSCH (or thePUSCH), which are provided by respective DCI field in the schedulingDCI. The other information may include the information as like the DMRSconfiguration, overhead from CSI-RS, CORESET, which are provided by RRCparameters.

As above-mentioned, the base station and/or the UE may determine the TBSfor a transport block in the PDSCH or the PUSCH at least based on thereceived I_(MCS) in the scheduling DCI. For example, as depicted in FIG.5, for 0≤I_(MCS)≤28, each index (entry) I_(MCS) may provide a modulationorder Q_(m), target code rate R, and a value for spectral efficiency.For 29≤I_(MCS)≤31, each index (entry) I_(MCS) may provide a modulationorder Q_(m), and may not provide a target code rate R and a value forspectral efficiency. In other others, the target code rate R and thevalue for spectral efficiency are reserved for I_(MCS) in 28≤I_(MCS)≤31.Hereinafter, those I_(MCS) where the target code rate R and the valuefor spectral efficiency are reserved (or are not provided) may be termedas reserved I_(MCS). Those I_(MCS) where the target code rate R and thevalue for spectral efficiency are provided may be termed as non-reservedMCS index (entry) I_(MCS). In the MCS index table 500, the reservedI_(MCS) are those I_(MCS) corresponding to 29≤I_(MCS)≤31. In the MCSindex table 500, the non-reserved MCS index I_(MCS) are those I_(MCS)corresponding to 0≤I_(MCS)≤28. Therefore, the MCS index table may have29 non-reserved MCS index I_(MCS), each of which explicitly providesQ_(m) and R, and may have 3 reserved MCS index I_(MCS), each of whichexplicitly provides Q_(m) but does not provide R.

For different predefined MCS index tables, the reserved MCS I_(MCS) maybe different. For example, for a predefined MCS index table which isdifferent from the MCS index table 500, MCS index I_(MCS) correspondingto I_(MCS)=28, I_(MCS)=29, I_(MCS)=30, I_(MCS)=31, may provide Q_(m)=2,Q_(m)=4, Q_(m)=6, Q_(m)=8, respectively, and may not provide the targetcode rate R and the value for spectral efficiency. These MCS indexI_(MCS) corresponding to I_(MCS)=28, I_(MCS)=29, I_(MCS)=30, I_(MCS)=31,may be termed as reserved I_(MCS).

Given each reserved MCS index I_(MCS) does not provide the target coderate R, the reserved MCS index I_(MCS) may not be used to redetermine(recalculate) a TBS for a transport block. Therefore, the reservedI_(MCS) may be at least used for a retransmission of a same transportblock. An advantage of using the reserved I_(MCS) is that the UE and thebase station may not redetermine a TBS for a same transport block sothat a transport block in an initial transmission has same TBS with thesame transport block in the retransmission. By keeping the same TBS, theUE and/or the base station may combine the current receivedretransmission data with the previous data (e.g. initial transmissiondata) and may attempt to decode the combined data for the same transportblock.

For a PDSCH (or a PUSCH) scheduled by a DCI format, the UE and the basestation may determine the TBS for the transport block ate least based onthe ‘Modulation and coding scheme’ field in the scheduling DCI. If thescheduling DCI indicates the I_(MCS) in 0≤I_(MCS)≤28 (as a non-reservedMCS index I_(MCS)), the UE and the base station may determine TBS forthe transport block. If the scheduling DCI indicates the I_(MCS) in29≤I_(MCS)≤31 (as a reserved MCS index I_(MCS)), the UE and the basestation may assume that the TBS for the transport block is determinedfrom the DCI transported in the latest PDCCH for the same transportblock using 0≤I_(MCS)≤28. That is, if the scheduling DCI indicates theI_(MCS) in 29≤I_(MCS)≤31, the UE and the base station may notredetermine the TBS for the transport block and reuse the determinedTBS, which has already been determined from the DCI transported in thelatest PDCCH for the same transport block using 0≤I_(MCS)≤28. If thescheduling DCI indicates the I_(MCS) in 0≤I_(MCS)≤28, the UE and thebase station may determine or redetermine the TBS for the transportblock. Therefore, the non-reserved MCS index may be explicitly used todetermine a TBS for a transport block, while the reserved MCS index maybe implicitly used to determine a TBS for a transport block. For atransport block scheduled by a DCI format indicating the I_(MCS) in0≤I_(MCS)≤28, a UE may determine the TBS for the transport block atleast based on the Q_(m) and R. The transmission of the transport blockmay be an initial transmission or a retransmission. For a transportblock scheduled by a DCI format indicating the I_(MCS) in 29≤I_(MCS)≤31,a UE may assume that the TBS for the transport block is determined froma DCI format transported in the latest PDCCH for the same transportblock using 0≤I_(MCS)≤28. The transmission of the transport block may bea retransmission.

The ‘Modulation and coding scheme’ field may be set to 5 bits for DCIformats used to schedule eMBB traffic data. In other words, the DCIformats as like DCI format 1_0, DCI format 0_0, DCI format C and DCIformat D may have a ‘Modulation and coding scheme’ with 5 bits so that‘Modulation and coding scheme’ field can indicate every MCS indexI_(MCS) in a predefined MCS index table. However, for some DCI formatsused to schedule URLLC traffic data, the ‘Modulation and coding scheme’field may be no need to set to fixed 5 bits and may be have variablebits (bit width, size). The number of the various bits may be determinedbased on the corresponding RRC configuration. Comparing with the DCIformats used for scheduling eMBB traffic data, DCI formats used forscheduling URLLC traffic data may require a much higher reliability. Itwould be beneficial to reduce the bit width of same fields so that thereliability can be achieved. For example, the bit width of the‘Modulation and coding scheme’ can be reduced for the DCI format E andDCI format F. By reducing the bit width of DCI fields in the DCIformats, the transmission reliability of the DCI formats may beimproved.

In the present disclosure, DCI format 0_0, DCI format 1_0, DCI format Cand DCI format D, may have the ‘Modulation and coding scheme’ field with5 bits. The DCI format E and F may have a ‘Modulation and coding scheme’field with variable bits. The number of the variable bits can beconfigurable and based on the corresponding RRC parameters.

FIG. 6 is a flow diagram illustrating one implementation of a method 600for determining Q_(m), R, and TBS by a UE 102.

The UE 102 may receive 602, from the base station 160, a RRC messageincluding one or more RRC parameter(s). At 602, the UE 102 may receive,from the base station 160, a RRC message including a RRC parameter (forexample RRC parameter A) relating to MCS configuration. The RRCparameter A may contain one or more entries (rows, elements, index) ofMCS configuration. That is, the RRC parameter A may be a list ofconfigured MCS entries. Each entry of MCS may indicate a modulationorder Q_(m), a target code rate R, and a value for spectral efficiency.In other words, the RRC parameter A may not indicate some MCS entries,which provide modulation order Q_(m) but not provide target code rate R.Hereinafter, the RRC parameter A containing one or more entries (rows,elements) of MCS configuration may refer to RRC configured MCS indextable. The entries of MCS configuration configured by RRC parameter (forexample, RRC parameter A) may be applied to a first DCI format group(for example, the DCI format E and F). The entries of MCS configurationconfigured by RRC parameter may not be applied to a second DCI formatgroup (for example, the DCI format 0_0, DCI format 1_0, DCI format C andF). In other words, the RRC configured MCS index table may be applied tothe first DCI format group. The RRC configured MCS index table may notbe applied to the second DCI format group. The above-mentioneddetermined predefined MCS index table may be applied to the second DCIformat group. The above-mentioned determined predefined MCS index tablemay not be applied to the second DCI format group. However, in a casethat the RRC parameter A (the RRC configured MCS index table) is notprovided (transmitted), the UE 102 and the base station 160 maydetermine that the predefined MCS index table is applied to the firstDCI format group.

FIG. 7 is a diagram illustrating one example of configured MCS indextable by RRC parameter 700. For example, as depicted in FIG. 7, the RRCparameter A 702, received from base station, may contain 8 entries ofMCS configuration. Each entry of MCS configuration in 702 may provide amodulation order Q_(m), a target code rate R, and a value for spectralefficiency. The UE 102 may determine the bit width of the ‘Modulationand coding scheme’ field for DCI formats in the first DCI format groupbased on the number of entries in the RRC parameter A. For example, theUE may determine the bit width of the ‘Modulation and coding scheme’field for DCI formats in the first DCI format group as Formula (3)ceil(log₂(I)) wherein the I is the number of entries in the RRCparameter A. The function ceil(x) means the function that takes as inputa real number x and gives as output the least integer greater than orequal to x. The value k (k>=0) indicated by the ‘Modulation and codingscheme’ field corresponds to the configured (k+1)-th entry of MCSconfiguration. In other words, value 0 indicated by the ‘Modulation andcoding scheme’ field refers to the first entry (element) in this list ofthe first RRC parameter, value 1 indicated by the ‘Modulation and codingscheme’ field refers to the second element in this list, and so on.Here, the number of entries I in the RRC parameter A is 8. Therefore,the UE 102 may determine the bit width of the ‘Modulation and codingscheme’ field of the DCI formats in the first DCI format group as 3bits. The UE 102 may determine the bit width of the ‘Modulation andcoding scheme’ of the DCI formats in the second DCI format group as 5bits.

Additionally or alternatively, at 602, the UE 102 may receive, from thebase station 160, a RRC message including a RRC parameter (for exampleRRC parameter B) relating to MCS configuration. The RRC parameter B mayindicate a starting MCS index S and MCS index length L. The starting MCSindex S is used to indicate the UE 102 where the available MCS indexstarts in the predefined MCS index table. The MCS index length L is usedto indicate the number of available MCS index counting from the startingMCS index S in the predefined MCS index table. In other words, the RRCparameter B may include L MCS entries. The UE may determine the bitwidth of the ‘Modulation and coding scheme’ field for DCI formats in thefirst DCI format group as Formula (4) ceil(log₂(L)) wherein the L is theMCS index length indicated by the RRC parameter B. The value k (k>=0)indicated by the ‘Modulation and coding scheme’ field corresponds to the(k+S)-th index I_(MCS) in the predefined MCS index table. In otherwords, value 0 indicated by the ‘Modulation and coding scheme’ fieldrefers to the S-th index I_(MCS) in the predefined MCS index table,value 1 indicated by the ‘Modulation and coding scheme’ field refers tothe (S+1)-th index I_(MCS) in the predefined MCS index table and so on.

At 604, the UE 102 may monitor PDCCH candidates for a DCI format. At604, the UE 102 may monitor a PDCCH with a DCI format and may furtherreceive a transport block in a PDSCH scheduled by the PDCCH with the DCIformat. As above-mentioned, the UE 102 may determine the bit width ofthe ‘Modulation and coding scheme’ field for the received DCI formats.For those DCI formats in the second DCI format group, the UE 102 and thebase station 160 may determine the ‘Modulation and coding scheme’ fieldas 5 bits. For those DCI formats in the first DCI format group, the UE102 and the base station 160 may determine the ‘Modulation and codingscheme’ field based on the RRC parameter (e.g. RRC parameter A or RRCparameter B). However, in a case that the RRC parameter (e.g. RRCparameter A or RRC parameter B) is not provided, the UE 102 and the basestation 160 may determine the ‘Modulation and coding scheme’ field as 5bits for those DCI formats in the first DCI format group.

At 606, the UE 102 may read the ‘Modulation and coding scheme’ field inthe scheduling DCI format (the received DCI format) to determine amodulation order Q_(m), a target code rate R used for the transportblock in the PDSCH (or the PUSCH). For a PDSCH (or a PUSCH) with atransport block scheduled by those DCI formats in the second DCI formatgroup, the UE 102 may read the ‘Modulation and coding scheme’ field toderive the I_(MCS) and determine the modulation order Q_(m), the targetcode rate R based on the predefined MCS index table.

Hereinafter, an implementation of determining a modulation order and/ortarget code rate for a PDSCH (or a PUSCH) with a transport blockscheduled by those DCI formats (those scheduling DCI formats) in thefirst DCI format group is described. At 606, for a transport block in aPDSCH (or a PUSCH) scheduled by those DCI formats in the first DCIformat group, the UE 102 may determine a modulation order Q_(m), atarget code rate R, and/or a TBS, which are used for the transport blockin the PDSCH (or the PUSCH), at least based on (i) a ‘Modulation codescheme’ field and one, a part, or all of a plurality of specified DCIfields other than the ‘Modulation code scheme’ field. The plurality ofspecified DCI fields may include one, a part, or all of (ii) a ‘HARQprocess number’ field, (iii) a ‘New data indicator’ field, (iv) a ‘timedomain resource assignment’ field, and (v) a ‘frequency domain resourceassignment’ field.

Here, a first RRC parameter may be an above-mentioned RRC parameter A. Afirst RRC parameter may be an above-mentioned RRC parameter B.

Regarding (i), the ‘Modulation code scheme’ field may indicate a value Xof MCS index I_(MCS). In other words, the ‘Modulation code scheme’ fieldmay indicate that I_(MCS)=X.

Regarding the factor (ii), the ‘HARQ process number’ field is used toindicate a HARQ process ID. The HARQ entity of the UE 102 may maintain anumber of parallel HARQ processes. Each HARQ process is associated witha HARQ process ID. The MAC entity of the UE 102 may allocate a transportblock scheduled by a DCI format to a HARQ process ID indicated by thesame DCI format.

Regarding the factor (iii), the ‘New data indicator’ field with 1 bit isused to indicate a value of the NDI (new data indicator) as 0 or 1. Fora HARQ process ID, the UE 102 may, if NDI has been toggled compared tothe value of the previous received transmission, consider thistransmission of the transport block to be a new transmission. If thetransmission of the transport block is the very first receivedtransmission, the UE 102 may consider this transmission of the transportblock to be a new transmission. In other words, the NDI field mayindicate a PDSCH (or a PUSCH) as an initial transmission of a transportblock or a retransmission of a transport block. A PDSCH (or a PUSCH)transmission may be indicated as an initial transmission of a transportblock or a retransmission of a transport block based on the NDI field.The base station may indicate, to a UE, that a PDSCH (or a PUSCH) is aninitial transmission of a transport block or a retransmission of atransport block via the NDI field of a DCI format scheduling thetransport.

Regarding the factor (v), some other specified DCI fields of thescheduling DCI may be one, a part, or all of a ‘time domain resourceassignment’ field, and a ‘frequency domain resource assignment’ field. A‘time domain resource assignment’ field may indicate a number ofallocated symbols L. A ‘frequency domain resource assignment’ field mayindicate a number of allocated resource blocks n_(PRB).

In a first case that a PDSCH (or a PUSCH) is determined as an initialtransmission of a transport block based on the NDI field of the firstDCI format (the scheduling DCI format), the UE 102 may determine themodulation order and the target code rate as X-th entry in the first RRCparameter. That is, the MCS Index X-th entry in the first RRC parametermay provide the modulation order and the target code rate used for thetransport block in the PDSCH (or the PUSCH). For example, the UE mayselect an MCS index I_(MCS)=X from the first RRC parameter (e.g. 702).The determined target code rate may be used to determine a transportblock size for the transport block in the PDSCH (or the PUSCH).

In a second case that a PDSCH (or a PUSCH) is determined as aretransmission of a transport block based on the NDI field of the firstDCI format (the scheduling DCI format), the UE 102 may determine themodulation order as X-th entry in the first RRC parameter. That is, theX-th MCS (Index) entry in the first RRC parameter may provide themodulation order used for the transport block in the PDSCH (or thePUSCH). That is, the X-th MCS Index entry in the first RRC parameter maynot provide the target code rate used for the transport block in thePDSCH (or the PUSCH). In other words, the target code rate provided inthe X-th MCS Index entry in the first RRC parameter is not used for thetransport block in the PDSCH (or the PUSCH). The UE 102 may discard thetarget code rate in the X-th MCS entry for the transport block in thePDSCH (or the PUSCH).

In the second case, the target code rate provided in the X-th MCS entryin the first RRC parameter may not be used to determine (or calculate)the TBS for the transport block size in the PDSCH (or the PUSCH). The UE102 and the base station 160 may not redetermine (or recalculate) a TBSfor the transport block. The UE 102 and the base station 160 may reuse aTBS, which is determined from a second DCI format transported in thelatest PDCCH for initial transmission of the transport block. In otherwords, a target code rate which is used to determine the TBS for thetransport block is determined based on the second DCI format schedulingan initial transmission of the transport block. Therefore, the UE 102and the base station 160 may determine to whether use the target coderate R in the X-th MCS entry in the first RRC parameter based on whetherthe transmission of the transport block is an initial transmission or aretransmission.

Additionally or alternatively, in a third case that a PDSCH (or a PUSCH)is determined as an initial transmission of a transport block based onthe NDI field of the first DCI format (the scheduling DCI format), theUE 102 may determine the modulation order and the target code rate asX-th entry in the first RRC parameter. That is, the UE may select an MCSindex I_(MCS)=X from the first RRC parameter (e.g. 702). The MCS indexI_(MCS)=X may provide the modulation order and the target code rate usedfor the transport block in the PDSCH (or the PUSCH).

In a fourth case that a PDSCH (or a PUSCH) is determined as aretransmission of a transport block based on the NDI field of the firstDCI format (the scheduling DCI format), the UE 102 may consider (assume)that a first number of MCS entries in the first RRC parameter isreplaced (interpreted) by a same number of reserved MCS index(entry).The first number can be determined based on a number of reserved MCSindex I_(MCS) in a predefined MCS index table. For example, in thepredefined MCS index table 500, the number of reserved MCS index with29≤I_(MCS)≤31 is 3. That is, the UE 102 may consider that 3 MCS entriesin the first RRC parameter is replaced by 3 reserved MCS index of thepredefined MCS index table 500. These 3 reserved MCS indexes may providemodulation order Q_(m) as 2, 4, 6 respectively. These 3 reserved MCSindexes may not provide target code rate R. These 3 reserved MCS indexesmay be in the first three entries in the first RRC parameter asillustrated in 704 of FIG. 7. That is, the first 3 MCS entries may bereplaced by the reserved MCS indexes. These 3 reserved MCS indexes inthe first RRC parameter may be in the last three entries in the firstRRC parameter as illustrated in 706 of FIG. 7. That is, the last 3 MCSentries in the first RRC parameter may be replaced by the reserved MCSindexes. The location of these 3 reserved MCS indexes in the first RRCparameter is determined based on the I_(MCS) (the value X) indicated bya DCI format transported in the latest PDCCH for the same transportblock using 0≤I_(MCS)≤28. For example, if the I_(MCS) indicated by theDCI format is in the first half entries of the first RRC parameter, theUE may consider that the last three MCS entries in the first RRCparameter are replaced by these 3 reserved MCS indexes. For example, ifthe I_(MCS) indicated by the DCI format is in the latter half entries ofthe first RRC parameter, the UE may consider that the first three MCSentries in the first RRC parameter are replaced by these 3 reserved MCSindexes.

Next, the UE 102 may select an MCS index I_(MCS)=X from the first RRCparameter 704 or 706. The MCS index I_(MCS)=X may provide the modulationorder and the target code rate used for the transport block in the PDSCH(or the PUSCH).

Additionally or alternatively, even for a retransmission of thetransport block indicated by the NDI field, the UE 102 may determinewhether to replace some MCS entries in the first RRC parameter by thereserved MCS indexes further based on factor (v) some other specifiedDCI fields. For example, the UE 102 may determine whether to replacesome MCS entries in the first RRC parameter further based on the ‘timedomain resource assignment’ field. In a case that the number ofallocated symbols L is same with that indicated by a ‘time domainresource assignment’ field of a DCI format transported in the latestPDCCH for the same transport block using 0≤I_(MCS)≤28, the UE 102 maydetermine to replace the MCS entries in the first RRC parameter by thosereserved MCS indexes. That is, the UE 102 may select an MCS indexI_(MCS)=X from the first RRC parameter 704 or 706. In a case that thenumber of allocated symbols L is different from that indicated by a‘time domain resource assignment’ field of a DCI format transported inthe latest PDCCH for the same transport block using 0≤I_(MCS)≤28, the UE102 may not determine to replace the MCS entries in the first RRCparameter by those reserved MCS indexes. That is, the UE may select anMCS index I_(MCS)=X from the first RRC parameter (e.g. 702).

Additionally or alternatively, even for a retransmission of thetransport block indicated by the NDI field, the UE 102 may determinewhether to replace some MCS entries in the first RRC parameter by thereserved MCS indexes further based on the ‘frequency domain resourceassignment’ field. For example, in a case that the number of allocatedresource blocks n_(PRB) is same with that indicated by a ‘frequencydomain resource assignment’ field of a DCI format transported in thelatest PDCCH for the same transport block using 0≤I_(MCS)≤28, the UE 102may determine to replace the MCS entries in the first RRC parameter bythose reserved MCS indexes. That is, the UE 102 may select an MCS indexI_(MCS)=X from the first RRC parameter 704 or 706. In a case that thenumber of allocated resource blocks n_(PR)B is different from thatindicated by a ‘time domain resource assignment’ field of a DCI formattransported in the latest PDCCH for the same transport block using0≤I_(MCS)≤28, the UE 102 may not determine to replace the MCS entries inthe first RRC parameter by those reserved MCS indexes. That is, the UEmay select an MCS index I_(MCS)=X from the first RRC parameter (e.g.702).

Additionally or alternatively, even for a retransmission of thetransport block indicated by the NDI field, the UE 102 may determinewhether to replace some MCS entries in the first RRC parameter by thereserved MCS indexes further based on the ‘frequency domain resourceassignment’ field and the ‘time domain resource assignment’ field. Forexample, in a case that the total number of REs (e.g. L×n_(PRB)) is samewith that indicated by a DCI format transported in the latest PDCCH forthe same transport block using 0≤I_(MCS)≤28, the UE 102 may determine toreplace the MCS entries in the first RRC parameter by those reserved MCSindexes. That is, the UE 102 may select an MCS index I_(MCS)=X from thefirst RRC parameter 704 or 706. In a case that the total number of REs(e.g. L×n_(PRB)) is different from that indicated by a DCI formattransported in the latest PDCCH for the same transport block using0≤I_(MCS)≤28, the UE 102 may not determine to replace the MCS entries inthe first RRC parameter by those reserved MCS indexes. That is, the UEmay select an MCS index I_(MCS)=X from the first RRC parameter (e.g.702).

FIG. 8 is a flow diagram illustrating one implementation of a method 800for determining Q_(m), R, and TBS by a base station 160.

The base station 160 may determine 802 a first RRC parameter (e.g. theabove-mentioned RRC parameter A or the above-mentioned RRC parameter B).The RRC parameter A may be a list of configured MCS entries. Each entryof MCS may indicate a modulation order Q_(m), a target code rate R, anda value for spectral efficiency. The base station 160 may determine theMCS entries based on the channel state information reported by the UE106. The base station 160 may determine the RRC parameter A for the UE102. The RRC parameter A may be applied to those DCI formats in theabove mentioned first DCI format group.

Additionally or alternatively, at 802, the base station 160 maydetermine the RRC parameter B relating to MCS configuration for the UE102. The RRC parameter B may indicate a starting MCS index S and MCSindex length L. The starting MCS index S is used to indicate the UE 102where the available MCS index starts in the predefined MCS index table.The MCS index length L is used to indicate the number of available MCSindex counting from the starting MCS index Sin the predefined MCS indextable.

The base station 160 may generate 804 a RRC message including the firstRRC parameter. A RRC message may include system information. The RRCmessage may be sent on a broadcast control channel (BCCH) logicalchannel, a common control channel (CCCH) logical channel or a dedicatedcontrol channel (DCCH) logical channel.

At 804, the base station 160 may plan to indicate the UE 102 to receivea transport block in a PDSCH or to transmit a transport block in aPUSCH. In this case, the base station 160 may determine a modulationorder Q_(m), a target code rate R used for the transport block in thePDSCH or the PUSCH. In other words, the base station 160 may determine amodulation order Q_(m), target code rate R, spectral efficiency from adetermined MCS index table and then may generate a ‘Modulation andcoding scheme’ field based on the determined modulation order Q_(m),target code rate R. For those DCI formats in the second DCI formatgroup, the base station 160 may determine (select) a MCS index from thepredefined MCS index table and the may generate a ‘Modulation and codingscheme’ field indicating the determined MCS index. For those DCI formatsin the first DCI format group, the base station 160 may determine(select) a MCS index from the first RRC parameter and the may generate a‘Modulation and coding scheme’ field indicating the determined MCSindex.

The base station 160 may broadcast system information including the RRCparameters related to MCS configuration described above. Alternatively,or additionally, the base station 160 may 806 transmit, to a userequipment (UE), a radio resource control (RRC) message including the RRCparameters related to MCS configuration. At 806, the base station 160may transmit, to the UE 102, a DCI format including the generated‘Modulation and coding scheme’ field in a PDCCH. The UE may upondetection of a PDCCH with the DCI format, may read the ‘Modulation andcoding scheme’ field in the scheduling DCI format to determine themodulation order Q_(m) and/or the target code rate R.

FIG. 9 illustrates various components that may be utilized in a UE 902.The UE 902 described in connection with FIG. 9 may be implemented inaccordance with the UE 102 described in connection with FIG. 1. The UE902 includes a processor 981 that controls operation of the UE 902. Theprocessor 981 may also be referred to as a central processing unit(CPU). Memory 987, which may include read-only memory (ROM), randomaccess memory (RAM), a combination of the two or any type of device thatmay store information, provides instructions 983 a and data 985 a to theprocessor 981. A portion of the memory 987 may also include non-volatilerandom access memory (NVRAM). Instructions 983 b and data 985 b may alsoreside in the processor 981. Instructions 983 b and/or data 985 b loadedinto the processor 981 may also include instructions 983 a and/or data985 a from memory 987 that were loaded for execution or processing bythe processor 981. The instructions 983 b may be executed by theprocessor 981 to implement one or more of the methods 200 describedabove.

The UE 902 may also include a housing that contains one or moretransmitters 958 and one or more receivers 920 to allow transmission andreception of data. The transmitter(s) 958 and receiver(s) 920 may becombined into one or more transceivers 918. One or more antennas 922 a-nare attached to the housing and electrically coupled to the transceiver918.

The various components of the UE 902 are coupled together by a bussystem 989, which may include a power bus, a control signal bus and astatus signal bus, in addition to a data bus. However, for the sake ofclarity, the various buses are illustrated in FIG. 9 as the bus system989. The UE 902 may also include a digital signal processor (DSP) 991for use in processing signals. The UE 902 may also include acommunications interface 993 that provides user access to the functionsof the UE 902. The UE 902 illustrated in FIG. 9 is a functional blockdiagram rather than a listing of specific components.

FIG. 10 illustrates various components that may be utilized in a basestation 1060. The base station 1060 described in connection with FIG. 10may be implemented in accordance with the base station 160 described inconnection with FIG. 1. The base station 1060 includes a processor 1081that controls operation of the base station 1060. The processor 1081 mayalso be referred to as a central processing unit (CPU). Memory 1087,which may include read-only memory (ROM), random access memory (RAM), acombination of the two or any type of device that may store information,provides instructions 1083 a and data 1085 a to the processor 1081. Aportion of the memory 1087 may also include non-volatile random accessmemory (NVRAM). Instructions 1083 b and data 1085 b may also reside inthe processor 1081. Instructions 1083 b and/or data 1085 b loaded intothe processor 1081 may also include instructions 1083 a and/or data 1085a from memory 1087 that were loaded for execution or processing by theprocessor 1081. The instructions 1083 b may be executed by the processor1081 to implement one or more of the methods 300 described above.

The base station 1060 may also include a housing that contains one ormore transmitters 1017 and one or more receivers 1078 to allowtransmission and reception of data. The transmitter(s) 1017 andreceiver(s) 1078 may be combined into one or more transceivers 1076. Oneor more antennas 1080 a-n are attached to the housing and electricallycoupled to the transceiver 1076.

The various components of the base station 1060 are coupled together bya bus system 1089, which may include a power bus, a control signal busand a status signal bus, in addition to a data bus. However, for thesake of clarity, the various buses are illustrated in FIG. 10 as the bussystem 1089. The base station 1060 may also include a digital signalprocessor (DSP) 1091 for use in processing signals. The base station1060 may also include a communications interface 1093 that provides useraccess to the functions of the base station 1060. The base station 1060illustrated in FIG. 10 is a functional block diagram rather than alisting of specific components.

The term “computer-readable medium” refers to any available medium thatcan be accessed by a computer or a processor. The term“computer-readable medium,” as used herein, may denote a computer-and/or processor-readable medium that is non-transitory and tangible. Byway of example, and not limitation, a computer-readable orprocessor-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer or processor. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray® disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.

It should be noted that one or more of the methods described herein maybe implemented in and/or performed using hardware. For example, one ormore of the methods described herein may be implemented in and/orrealized using circuitry, a chipset, an application-specific integratedcircuit (ASIC), a large-scale integrated circuit (LSI) or integratedcircuit, etc.

Each of the methods disclosed herein comprises one or more steps oractions for achieving the described method. The method steps and/oractions may be interchanged with one another and/or combined into asingle step without departing from the scope of the claims. In otherwords, unless a specific order of steps or actions is required forproper operation of the method that is being described, the order and/oruse of specific steps and/or actions may be modified without departingfrom the scope of the claims.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the systems, methods and apparatus described herein withoutdeparting from the scope of the claims.

1-12. (canceled)
 13. A user equipment (UE), comprising: receptioncircuitry configured to receive, from a base station, system informationand a physical downlink control channel (PDCCH) with a first DCI format,the first DCI format being used for scheduling of a physical uplinkshared channel (PUSCH); and control circuitry configured to, in a casethat the system information includes a first radio resource control(RRC) parameter wherein the first RRC parameter contains one or moreentries of modulation and coding scheme (MCS) configuration, determinewhich entry from the one or more entries based on a value of an MCSfield included in the first DCI format, in a case that the systeminformation does not include the first RRC parameter, determine whichentry from a predefined MCS table based on a value of the MCS field. 14.The UE according to claim 13: each entry of MCS configurationcorresponds to an MCS index and indicates a modulation order and atarget code rate used for a transport block (TB) in the PUSCH.
 15. TheUE according to claim 14: the control circuitry is further configured todetermine a modulation order and a target code rate used for the TB inthe PUSCH at least based on the MCS field and one, a part, or all of aplurality of specified DCI fields other than the MCS field, wherein thespecified DCI fields include one, a part, or all of a HARQ processnumber field, a new data indicator (NDI) field, a time domain resourceassignment field, and a frequency domain resource assignment field. 16.The UE according to claim 15: in a first case that the PUSCH isdetermined as an initial transmission of the TB based on the NDI fieldof the first DCI format, the modulation order and the target code rateare determined as X-th MCS entry in the first RRC parameter, thedetermined code rate is at least used to determine the transport blocksize for the TB, in a second case that the PUSCH is determined as aretransmission of the TB based on the NDI field of the first DCI format,the modulation order is determined as X-th MCS entry in the first RRCparameter, the target code rate provided in the X-th MCS entry is notused for the TB in the PDSCH, wherein the value of X is indicated by theMCS field.
 17. A base station, comprising: transmission circuitryconfigured to transmit, to a user equipment (UE), system information anda physical downlink control channel (PDCCH) with a first DCI format, thefirst DCI format being used for scheduling of a physical uplink sharedchannel (PUSCH); and control circuitry configured to determine, in acase that the system information includes a first RRC parameter whereinthe first RRC parameter contains one or more entries of modulation andcoding scheme (MCS) configuration, an entry from the one or moreentries, in a case that the system information does not include thefirst RRC parameter, an entry from a predefined MCS table, generate avalue of an MCS field included in the first DCI format based on thedetermined entry.
 18. The base station according to claim 17: each entryof MCS configuration corresponds to an MCS index and indicates amodulation order and a target code rate used for a transport block (TB)in the PUSCH.
 19. The base station according to claim 18: the controlcircuitry is further configured to determine a modulation order and atarget code rate used for the TB in the PUSCH at least based on thefirst RRC parameter and one, a part, or all of a plurality of specifiedDCI fields other than the MCS field, generate the MCS field with an MCSindex indicating the determined modulation order and the target coderate, wherein the specified DCI fields include one, a part, or all of aHARQ process number field, a new data indicator (NDI) field, a timedomain resource assignment field, and a frequency domain resourceassignment field.
 20. The base station according to claim 19: in a firstcase that the PUSCH is determined as an initial transmission of the TBbased on the NDI field of the first DCI format, the modulation order andthe target code rate are determined as X-th MCS entry in the first RRCparameter, the determined code rate is at least used to determine thetransport block size for the TB, in a second case that the PUSCH isdetermined as a retransmission of the TB based on the NDI field of thefirst DCI format, the modulation order is determined as X-th MCS entryin the first RRC parameter, the target code rate provided in the X-thMCS entry is not used for the TB in the PDSCH, wherein the value of X isindicated by the MCS field.
 21. A method by a user equipment (UE),comprising: receiving, from a base station, system information and aphysical downlink control channel (PDCCH) with a first DCI format, thefirst DCI format being used for scheduling of a physical uplink sharedchannel (PUSCH); determining, in a case that the system informationincludes a first radio resource control (RRC) parameter wherein thefirst RRC parameter contains one or more entries of modulation andcoding scheme (MCS) configuration, which entry from the one or moreentries based on a value of a MCS field included in the first DCIformat; and determining, in a case that the system information does notinclude the first RRC parameter, which entry from a predefined MCS tablebased on a value of the MCS field.